Mpxj

* Retrieve role availability data when reading a schedule from a P6 database.
* Populate the project's Name and Title attributes when exporting an MSPDI file.
* Ensure the Project ID attribute is populated when writing an XER file.
* Don't include null tasks (blank tasks) when writing an XER file.
* Strip control characters from entity names written to MSPDI files and XER files.
* Ensure resource material labels written to MSPDI files meet Microsoft Project's naming requirements.
* Ensure the activity code value Name attribute is populated when read from an Asta PP file.
* Don't allow multiple values for an activity code when writing XER and PMXML files.
* The MSPDI and MPX writers now dynamically renumber Unique ID values which are too large for Microsoft Project. The original schedule is no longer modified to achieve this.

* Add the `UnitOfMeasure` class to represent the unit of measure for a material resource. The unit of measure corresponds to the current "material label" attribute of a resource. The `Resource.getMaterialLabel()` method will now retrieve the label from the `UnitOfMeasure` instance associated with the resource. The `Resource.setMaterialLabel()` method is now deprecated, the `Resource.setUnitOfMeasure()` or `Resource.setUnitOfMeasureUniqueID()` methods should be used instead.
* Unit of measure for material resources are now read from and written to Primavera schedules.
* Improve task duration and percent completion calculation for Asta PP files.
* Improve date parsing when reading XER files written by older versions of P6.
* Added the `setIgnoreErrors` method to the Primavera database reader class, and MSPDI, Schedule Grid, and SDEF file reader classes. The current default behavior of ignoring data type parse errors is unchanged. Calling `setIgnoreErrors(false)` on one of these reader classes will ensure that an exception is raised when a data type parse error is encountered.
* Added the `ProjectFile.getIgnoredErrors()` method. The default behavior for MPXJ reader classes is to ignore data type parse errors. If any errors have been ignored when reading a schedule, details of these errors can be retrieved by calling the `ProjectFile.getIgnoredErrors()` method.
* Handle duplicate relation unique IDs when reading schedules.
* Include resource availability table in JSON output.
* Add the Resource field Default Units, and ensure this field is read and written for P6 Schedules.
* Updated the Resource attribute Max Units to ensure that this is calculated from the resource's availability table. Note that the `Resource.getMaxUnits()` method will return the resource's Max Units attribute for the current date. To retrieve the Max Units for a different date, use the `AvailabilityTable.getEntryByDate()` method.
* Marked the `Resource.setMaxUnits()` method as deprecated. The Max Units attribute is derived from the resource's availability table. Changes to Max Units should now be made by modifying the availability table.
* Updated the Resource attribute Available From to ensure that this is calculated from the resource's availability table. Note that the `Resource.getAvailableFrom()` method will return the resource's Available From attribute for the current date. To retrieve the Available From attribute for a different date, use the `AvailabilityTable.availableFrom()` method.
* Marked the `Resource.setAvailableFrom()` method as deprecated. The Available From attribute is derived from the resource's availability table. Changes to the Available From attribute should now be made by modifying the availability table.
* Updated the Resource attribute Available To to ensure that this is calculated from the resource's availability table. Note that the `Resource.getAvailableTo()` method will return the resource's Available To attribute for the current date. To retrieve the Available To attribute for a different date, use the `AvailabilityTable.availableTo()` method.
* Marked the `Resource.setAvailableTo()` method as deprecated. The Available To attribute is derived from the resource's availability table. Changes to the Available To attribute should now be made by modifying the availability table.

* Added the Project Properties attribute Relationship Lag Calendar and implemented read and write support for this for P6 schedules. (Contributed by Rohit Sinha).
* Improve compatibility of PMXML files with P6 EPPM by moving the Schedule Options tag.
* Ensure Baseline Projects in PMXML files include Schedule Options and Location Object ID.

* Updates to improve compatibility with versions of Java after Java 8.
* Ensure timestamps with fractional sections are read correctly from Phoenix PPX files (Based on a contribution by Rohit Sinha).
* Improve handling of double quotes when reading and writing XER files.
* To allow XER files written by MPXJ to be imported correctly by P6, ensure that they have a single top level WBS entry (Based on a contribution by Alex Matatov)
* Ensure that `ProjectProperties.getCustomProperties()` returns an empty Map rather than returning `null` if no custom properties have been configured.
* Ensure project calendars and project activity codes are nested within the project tag of PMXML files.

* Fix an issue preventing native SQLite library from loading when using the .Net version of MPXJ on macOS.

* Write schedule options to PMXML and XER files.
* Fix an arithmetic error in RateHelper when converting a rate from minutes to hours.
* Introduced new methods to RateHelper accepting a `TimeUnitDefaultsContainer` argument rather than a `ProjectFile` for greater flexibility. Marked methods taking a `ProjectFile` argument as deprecated.
* Ensure Early Finish and Late Finish are populated for Asta milestones and tasks.
* Don't attempt to calculate total slack if start slack or finish slack are missing.
* Ensure completed tasks are not marked as critical.
* Improve handling of non-standard Boolean values in MPX files.
* Improve Total Slack calculation for P6 projects.
* Handle finish milestones with `null` actual start date for actual duration calculation when reading PMXML files (Contributed by Andrew Marks).