#309 Use lua_pushglobaltable for Lua

[Miles Bader]

One of the Lua maintainers has recommended using "lua_pushglobaltable" to push the globals table, as being more future-proof than the method currently used by SWIG.

lua_pushglobaltable is new in Lua 5.2, so this patch:

(1) Adds a definition of lua_pushglobaltable for older versions of Lua to Lib/lua/luarun.swg

(2) Changes Lib/lua/luaruntime.swg to use it

With patch, the Lua test-suite results are unchanged for both Lua 5.1 and 5.2.

[Miles Bader]

Use lua_pushglobaltable for Lua

[William Fulton]

Okay, committed for swig-2.0.5