Remove exceptions support from QtQml

Remove exceptions support from QtQml

Previously, the sequence wrapper handled std::alloc exceptions.
This commit removes that handling, as there are many other ways
to use up all of the available address space memory which aren't
handled (eg, loading lots of large images), and exception support
causes a large overhead.

See a1151929fffc765e128d72d170342020b34dd0b3 for more information.

Change-Id: I68c9d7744e7dcece7b3112352e01ac71ead12f62
Reviewed-by: Glenn Watson <glenn.watson@nokia.com>
Reviewed-by: Martin Jones <martin.jones@nokia.com>