- use hidapi grantlee and mdbtools from MXE
- update MXE version to use QT 5.15, and pull in libzstd and CMake 3.17.3
- fix linking of winmm on windows build with new mxe
- add some instructions on building the container
- add some new dependancies from QT 5.15 to the packaging
- add a patch to MXE to Build qtconnectivity with native-win32-bluetooth
[Dirk Hohndel: small refactor]
Signed-off-by: Paul Buxton <paulbuxton.mail@googlemail.com>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>