Stop trying to report Xlib errors

Xlib being completely asynchronous, trying to report errors can't do anything
right without huge overhead.

TODO

@@ -1,6 +1,4 @@
 Still to do:
- * Cleanly report Xlib errors
- * Setup a scheme for error reporting
- * Support for faces other than the first
  * Document
+ * Support for faces other than the first
  * Add FontConfig optional support for last-resort fallback font (?)