Asammdf

Fixes
- fix error in _MDF3_ _save_ method
- fix _select_ method to return the signals in the same order as the channels given
- fix _get_ method when channel group cycles number is 0

Changes
- added _select_ generator method to _MDF_
- added _config_ pacakge level function to handle all _asammdf_ configurations
- use data list and split data block when saving (configurable)

Fixes
- fix mdf v3 POLY Conversion
- fix mdf v4 _DataList_ for Python 2
- PEP8 improvements

Changes
- big performance boost for _convert_, _cut_, _export_, _filter_, _merge_ and _iter_to_pandas_ when _load_measured_data=True_

Fixes
- fix incomplete implementation of mdf version 4 _DLBLOCK_

Changes
- allow compacting of signed integers when appending
- use the package function _enable_integer_compacting_
- avoid unnecessary computation for polynomial conversions
- add _MLSD_ channel support
- improve plotting of maps and update _Signal_ usage example
- moved _\_\_version\_\__ to version.py

Fixes
- fix errors in HDF5 export
- fix error in get for singed integers of nonstandard size
- fix mask error for nonstandard integers
- fix error in MDF4 get method when channel type was virtual master