Rename displacement enumeration elements

* Rename "LEFT" to "DAY_PREV", "RIGHT" to "DAY_NEXT", "UP" to
  "WEEK_PREV" and "DOWN" to "WEEK_NEXT" to reflect the semantics of
  these operations. Remove the unneeded "MOVES" element.

* Reorder code to improve consistency.

Signed-off-by: Lukas Fleischer <calcurse@cryptocrack.de>

src/calcurse.h

@@ -399,10 +399,10 @@ enum key {
   KEY_GENERIC_REDRAW,
   KEY_GENERIC_ADD_APPT,
   KEY_GENERIC_ADD_TODO,
-  KEY_GENERIC_NEXT_DAY,
   KEY_GENERIC_PREV_DAY,
-  KEY_GENERIC_NEXT_WEEK,
+  KEY_GENERIC_NEXT_DAY,
   KEY_GENERIC_PREV_WEEK,
+  KEY_GENERIC_NEXT_WEEK,
   KEY_GENERIC_SCROLL_DOWN,
   KEY_GENERIC_SCROLL_UP,
   KEY_GENERIC_GOTO_TODAY,
@@ -534,13 +534,12 @@ enum wday {
 
 /* Possible movements inside calendar. */
 enum move {
-  UP,
-  DOWN,
-  LEFT,
-  RIGHT,
+  DAY_PREV,
+  DAY_NEXT,
+  WEEK_PREV,
+  WEEK_NEXT,
   WEEK_START,
-  WEEK_END,
-  MOVES
+  WEEK_END
 };
 
 /* Available color pairs. */