Log Message:
Changes 20081224:
* Check for a buggy system on Apple 10.5 with X11.
* Fix more memory problems in Merge Fonts.
* If a font were missing a .notdef glyph. If the user tried to display
  a font sample of text which included a character not in the font.
  Then (after the recent patches for grid-fit metrics in Print dlg)
  fontforge would crash.
* Fix a bug in old cubic to quadratic conversion.
* Lots of changes to extrema code.
* Initializing the font info dialog crashed on the mac when -O2 was
  specified during configure (the default situation).
* After adding an Apply button the Transform dlg would crash if invoked
  in a glyph with no undoes.