webkit: Update to WebKit svn r44552.

Closes #427

- Fix generation of configure script and Makefiles.
 - Add dependencies on libsoup and enchant.
 - Allow configuration of rendering target (currently X11 or DirectFB).

Signed-off-by: Will Newton <will.newton@gmail.com>
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>