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)