More efficient type name cache

Instead of creating completely separate hashes for all the types used
by every QML file, we simply link to the QDeclarativeTypeModule.  This
uses much less memory, and is faster to construct at startup.

Change-Id: I28bc2807074f9c6f38096d6e4ce8be744159d023
Reviewed-on: http://codereview.qt.nokia.com/3741


Reviewed-by: Roberto Raggi <roberto.raggi@nokia.com>