Lua C++ exception catching too broad.

["Joe Smith" <unknown_kev_cat@...>]

When compiling lua as C++ the exception catching is too broad.
in luaconf.h "catch(...)" is used as part of the definition of LUAI_TRY.

However, that could catch a programs own internal exceptions, which may have 
valid reasons to jump past lua in the unwind path.
Instead please use "catch(lua_longjmp*)"  which will only catch the internal 
lua errors.