Rationale: Various compilation errors fixed as per https://aur.archlinux.org/cgit/aur.git/commit/?h=warmux&id=bb434ffa6c95496624d083fd32df87b03e78e8a4

--- a/src/interface/weapon_menu.cpp.orig	2016-05-09 15:22:36.895266463 +0200
+++ b/src/interface/weapon_menu.cpp	2016-05-09 15:21:38.518476191 +0200
@@ -391,7 +391,7 @@
 Weapon * WeaponsMenu::UpdateCurrentOverflyItem(const Polygon * poly)
 {
   if (!show)
-    return false;
+    return NULL;
   const std::vector<PolygonItem *>& items = poly->GetItem();
   WeaponMenuItem * tmp;
   Interface::GetInstance()->SetCurrentOverflyWeapon(NULL);