Fixed crash if initialization of EGL failed but was tried again later.

The internal function SDL_EGL_LoadLibrary() did not delete and remove a mostly
uninitialized data structure if loading the library first failed. A later try to
use EGL then skipped initialization and assumed it was previously successful
because the data structure now already existed. This led to at least one crash
in the internal function SDL_EGL_ChooseConfig() because a NULL pointer was
dereferenced to make a call to eglBindAPI().

TODO.txt

@@ -0,0 +1,10 @@
+Future work roadmap:
+ * http://wiki.libsdl.org/moin.cgi/Roadmap
+
+ * Check 1.2 revisions:
+	3554 - Need to resolve semantics for locking keys on different platforms
+	4874 - Do we want screen rotation?  At what level?
+	4974 - Windows file code needs to convert UTF-8 to Unicode, but we don't need to tap dance for Windows 95/98
+	4865 - See if this is still needed (mouse coordinate clamping)
+	4866 - See if this is still needed (blocking window repositioning)
+