* NEW: Implement Font.TextWidth() and Font.TextHeight().
* NEW: Add the default Gambas font.
* NEW: Add a texture cache in each Font object, that can store the last 128
drawn texts. When the cache is full, it is completely erased.
* BUG: Many fixes.
git-svn-id: svn://localhost/gambas/trunk@6776 867c0c6c-44f3-4631-809d-bfa615b0a4ec