[qtmozembed] Commit preedit text when touching screen if we have preedit text.

Real fix should be such that we would commit text just before moving
the cursor position. As we're currently also missing underline
under preedited text, I think that this is reasonable for time
being.
Merge pull request #55 from rainemak/preeditFix

[qtmozembed] Commit preedit text when touching screen if we have preedit...