Remove old compiler and VME

This removes the bulk of the code. A few smaller cleanups remain, to be
done in smaller changes as they move code around.

Additionally the "optimize" option of qqmlbundle was removed. It called QQmlScript::Parser::preparseData,
which however was not implemented and always returned an empty QByteArray. Therefore "optimize" would not
do anything and the class is gone now :)

Change-Id: I0c265e756704cb53c5250be1f69e4a3e1b6e64d5
Reviewed-by: Lars Knoll <lars.knoll@digia.com>