[Qt] Fix build of modules depending on QtWebKit when using prefix

[Qt] Fix build of modules depending on QtWebKit when using prefix
https://bugs.webkit.org/show_bug.cgi?id=101437

Patch by Oswald Buddenhagen <oswald.buddenhagen@nokia.com> on 2012-11-07
Reviewed by Simon Hausmann.

.:

.qmake.conf loads qt_build_config.prf, which nowadays is responsible for
adding the path to .qmake.super (before it was done by default_pre.prf,
so having setting the path in our default_pre wrapper was sufficient).

* .qmake.conf:

Tools:

Remove setting of MODULE_QMAKE_OUTDIR from here, it's been moved to .qmake.conf.

* qmake/mkspecs/features/default_pre.prf:

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@133730 268f45cc-cd09-0410-ab3c-d52691b4dbfc