Enhanced special support

- Made the current charge being saved.
- Added script binds:
  - chr_set_special_recharge_speed
  - chr_get_special_recharge_speed
  - chr_set_special_mana
  - chr_get_special_mana
  - get_special_info
- Added special info lua class. Functions:
  - name
  - needed_mana
  - rechargeable
  - on_use
  - on_recharged
  - category

Further the engine no longer sets charge to 0 after using of specials
this allows more flexbilillity (like failing specials).

Changes on the xml database:
- recharge renamed to rechargeable (needed by client and server)
- needed - the needed mana to trigger a special (server only)
- rechargespeed - the defailt recharge speed in mana per tick (server only)
- target - the type of target (either being or point) (server and client)

I also made the lua engine pushing nil instead of a 0 light userdata when
the pointer was 0.

Database update needed.

Change is tested.

Mana-Mantis: #167, #156

Reviewed-by: bjorn.

1 files changed, 4 insertions, 1 deletions

diff --git a/src/scripting/luascript.cpp b/src/scripting/luascript.cpp
index 36adb912..3a45b3fc 100644
--- a/src/scripting/luascript.cpp
+++ b/src/scripting/luascript.cpp
@@ -89,7 +89,10 @@ void LuaScript::push(const std::string &v)
 void LuaScript::push(Thing *v)
 {
     assert(nbArgs >= 0);
-    lua_pushlightuserdata(mCurrentState, v);
+    if (v)
+        lua_pushlightuserdata(mCurrentState, v);
+    else
+        lua_pushnil(mCurrentState);
     ++nbArgs;
 }