efl: improve X detection by Joel Klinghed.

efl: improve X detection by Joel Klinghed.

* Split out ecore_imf_xim to do its own check

* Fixed problem with xcb's makekeys, no rule for
  $(top_builddir)/src/utils/ecore/makekeys$(EXEEXT) exists so make
  used an implicit rule (ignoring any cflags of course)

* Fixed gl_x11 engine to build with either Xlib or XCB (xcb flags were
  missing)

* Added EFL_FIND_X and replace any used of AC_PATH_X{,TRA}.  First
  looks for Xorg pkg-config files then if those arn't found it falls
  back to old AC_PATH_X. Also generalized common header and lib
  checks.  Could probably use some polishing (the AC_CACHE_VAL cruft
  especially) but this is what I have time for tonight.

Now X11 should be found on non-standard locations by means of xmkmf,
--x-includes/--x-libraries and also pkg-config.

SVN revision: 82475