build_wrapper: Use os.path.join instead of os.sep consistenly

Change-Id: I6606109e2d4ffe76c8e52fa22607af772d7b5472
Reviewed-by: Iikka Eklund <iikka.eklund@digia.com>
releases-520: Remove qtlocation from the exclude list

qtlocation is new candidate module for Qt 5.2.0

Change-Id: I9a6ea7999c8ba1550218ce26ac21faf88644c46c
Reviewed-by: Iikka Eklund <iikka.eklund@digia.com>