uterm: input: include keysym file from main header

We still depend on xproto during compile time as we need the keysym
definitions. We could simply copy the keysym file but I really want to
wait until xkbcommon is finally released as it includes a keysym header,
too. Then we can simply depend on xkbcommon during build.

However, as we still need a way to perform the other conversion: string to
keysym, we need some hashtable anyway. So we can then also copy the keysym
definitions, too.

Signed-off-by: David Herrmann <dh.herrmann@googlemail.com>

src/uterm.h

@@ -41,6 +41,7 @@
 #include <inttypes.h>
 #include <stdbool.h>
 #include <stdlib.h>
+#include <X11/keysym.h>
 #include "eloop.h"
 
 /*