Generate config.h

This allows us to remove a lot of #ifdef's. Either we want to use
a config.h or we don't. Since we'll want it for e.g. optional gsound
support later on let's have it.

eek/eek-symbol.c

@@ -25,9 +25,7 @@
  * The #EekSymbolClass class represents a symbol assigned to a key.
  */
 
-#ifdef HAVE_CONFIG_H
 #include "config.h"
-#endif  /* HAVE_CONFIG_H */
 
 #include "eek-symbol.h"
 #include "eek-serializable.h"