Update Qt licensing for offline and online installers

From now on use only combined LGPLv2 and LGPLv3 license
for all installations. Put the thirdparty license info
also into dedicated installer component.

Change-Id: I6665afc0a591ab29aee5934c9b6650ca0b96a84e
Reviewed-by: Jani Heikkinen <jani.heikkinen@digia.com>