Habapp

This version shows "0.13.1 Dev" because I forgot to change the version -.-

Changes
- If loading of an item fails HABApp doesn't skip loading of all items any more
- Added Loghandler: ``HABApp.core.lib.handler.MidnightRotatingFileHandler``:
A file handler that waits until the file has a certain size and then rotates at midnight.
This is the default when the logging.yml gets created
Made this the default file handler for logging.
- Removed timeout for connection to openhab
- Added example how to check Thing status

- Textual configuration of Things can be spread out over multiple files
- Extensive error messages and exception tracebacks with variable values
- Rework of MultiModeItem:
- moved into subpackage HABApp.util.multimode
- create_mode is deprecated, modes get added by add_mode and can be subclassed
- Added SwitchItemValueMode, a mode which can be enabled/disabled by a SwitchItem
- added functions to work with OH rest/links/ endpoint (thx snpz)
- added get_thing to the OpenhabInterface
- BaseValueItem can be used in calculations (and subsequently all other item types, too),
no more need to use the ``value`` property
e.g.
``val = NumberItem('item1') + NumberItem('item2')``
is the same as ``val = NumberItem('item1').value + NumberItem('item2').value``

Bugfix:
- First call for scheduler with time of day for workday/weekend could have been wrong
- ParamFiles get unloaded properly when file gets deleted

[Added possibility to textually config openhab things](
https://habapp.readthedocs.io/en/latest/interface_openhab.html#textual-thing-configuration)

- Bugfix for Dimmer item not getting properly loaded from openhab
- Added example how to create rules from parameter files

- HABApp finds the correct config if the command arg is the config.yml instead of the config folder
- Files and folders are loaded in alphabetical order
- Binary data from mqtt work now as expected
- removed 'auto_disable_on' from MultiModeItem
- Fixes issue where sun functions were triggered multiple times when using scheduler boundaries

* Created AggregationItem & small cleanup
* fixed Error None in __cleanup_objs
* reworked loading of rules
* Added some documentation