Asammdf

Fixes
* fixes 167
* fix documentation for select
* fix RTAB conversion

Stand-alone GUI builds
* [Linux](https://ci.appveyor.com/project/danielhrisca/asammdf/branch/master/job/mlypit1g3kyeqxj3/artifacts)
* [Windows](https://ci.appveyor.com/project/danielhrisca/asammdf/branch/master/job/7yq9trg9762v0c8w/artifacts)

Fixes
* fix for big endian channels that were not byte aligned
* fix handling of measurement start timestamp
* many fixes related to CAN bus logging measurements

Changes
* switch from pyqtgraph docks to mdi windows for sub-plots
* added numeric window to display just the channel values (can handle large channel count)
* channels can be drag & dropped between numeric and plot windows
* save and restore configuration
* restores all plot and numeric windows, with given titles
* restores channel color, enable state, common axis
* restores computed channels
* improved performance for _extract_can_logging_
* refactored _resample_ method
* the _raster_ can now be a channel name or an array
* added RMS and average values in channel statistics
* handle J1939 CAN messages
* improve zomming perforamnce in GUI
* add dark style theme and plot background option
* add ability to add advanced search channels to existing plots and numeric windows
* add _remove_source_from_channel_names_ argument to MDF class
* add _master_using_raster_ utility function
* improve performance for unsorted files





Stand-alone GUI builds
* [Linux](https://ci.appveyor.com/project/danielhrisca/asammdf/builds/24092272/job/rlrlw64x70ghspqo/artifacts)
* [Window](https://ci.appveyor.com/project/danielhrisca/asammdf/builds/24092272/job/mdfuc9f0d89si0kq/artifacts)

Fixes
* avoid warning "QLayout: Attempting to add QLayout "" to QWidget "", which already has a layout"
* prevent crash when plotting with the window maximized

Fixes
* axis label

Changes
* added _return_names_ argument to AdvancedSearch dialog

Fixes
* fix crash caused by closing the sub-plots

Fixes
* multiple fixes to handling of CAN bus logging measurements
* don't ignore channels argument in to_dataframe method
* fix to_dataframe in case of channels with invalidation bits
* export fixes for mat and hdf5
* do not read samples two times in export method for "parquet" or "single_time_base=True"
* fix get method for channel composition when the fields have conversion rules

Changes
* added sub-plots to GUI
* updated GUI documentation
* multiple enhancements to GUI
* add method to extract all raw can signals from anonymous can bus logging
* added validate method to Signal that will apply the invalidation_bits
* reduce memory usage for to_dataframe by converting float64 channel to float32 and checking the minimum dtype that can represent all samples for integer channels
* add compression option to export
* improve performance for channels with invalidation bits