C++ editor: Normalize line endings for find usages

C++ editor: Normalize line endings for find usages

Find usages and related rely on functions that assume \n as line
ending. This is true for the preprocessed files, but not for the
original sources.

Change-Id: I61b7e05c0116504d11c7df4b1aa10d519b705336
Reviewed-on: http://codereview.qt.nokia.com/260
Reviewed-by: Qt Sanity Bot <qt_sanity_bot@ovi.com>
Reviewed-by: Erik Verbruggen <erik.verbruggen@nokia.com>