Update license headers and add new licenses

- Renamed LICENSE.LGPL to LICENSE.LGPLv21
- Added LICENSE.LGPLv3 & LICENSE.GPLv2
- Removed LICENSE.GPL

Change-Id: I452f44a464e8da80ee4c0c38de6ec6abfd6ac285
Reviewed-by: Antti Kokko <antti.kokko@digia.com>
Reviewed-by: Tony Sarajärvi <tony.sarajarvi@digia.com>
Merge remote-tracking branch 'origin/5.4' into dev

Change-Id: I9e864085ed329349aaa49551a15a8521d140aaa7
Bump version

Change-Id: I0668ef08ef66d837de74816b805b634e0c0d50e8
Merge remote-tracking branch 'origin/5.3' into 5.4

Conflicts:
	.qmake.conf

Change-Id: I7fd0ea8631fc0f5e9228781afe66b3dda9d73f59
Merge remote-tracking branch 'origin/5.4' into dev

Change-Id: I7289625e062c5ce4126c240b459057258793dd85