Fix mixed indents and trailing whitespace (#56)

This fixes the tabs and trailing whitespace.

I've set a vim modeline to expand tabs and set tab width to 4 spaces.

ttyclock.c

@@ -680,3 +680,5 @@ main(int argc, char **argv)
 
      return 0;
 }
+
+// vim: expandtab tabstop=4 softtabstop=4 shiftwidth=4

ttyclock.h

@@ -145,3 +145,5 @@ const Bool number[][15] =
 };
 
 #endif /* TTYCLOCK_H_INCLUDED */
+
+// vim: expandtab tabstop=4 softtabstop=4 shiftwidth=4