Asammdf

Fixes
* fixes issue 203, 204, 206 and 207
* fix metadata of mdf v4 conversion
* do not ignore can logging on missing channel group acquisition name
* fix appveyor commands for linux build

Standalone GUI builds
* [Linux](https://ci.appveyor.com/project/danielhrisca/asammdf/builds/25815915/job/pgr33wbtdi6nyh1g/artifacts)
* [Windows](https://ci.appveyor.com/project/danielhrisca/asammdf/builds/25815915/job/pc4q3dk5roegb03r/artifacts)

Fixes
* fixes 198
* fix attribute error when CAN database could not be loaded (thanks to Julien)
* fix for issue 202

Changes
* initial mdf v4 file finalization support for a subset of unfinalization flags (thanks to Martin)

Fixes
* keep channel byte order after the chunk mode access

Fixes
* fix moving the cursor with the arrow keys
* fix pop-up message in case of exceptions

Fixes
* fixes issue 185 * add scrambling of embedded attachment data

Changes
* add title argument to the plot function
* add scrambling of embedded attachment data
* improve get_can_signal

Fixes
* fix for csv export with time_as_date and single_time_base
* fix export
* fix channel list view


Changes
* use canmatrix 0.8
* improve performance of mdf v4 TABX and RTABX conversion
* removed _excel_ export
* skip channel groups without channels when the export is called with single_time_base=False