Run Lua scripts in a sandbox

We dont properly do this at the moment and grant access to dangerous libraries as a result.

Relevant code area (the visible code would give a blank environment but is never used):

Lines 1240 to 1242 in 0a7bd76

    
           if (blank_env) { 
        
           	lua_newtable(L); 
        
           	lua_setfenv(L, lua_gettop(L) - Args - 1);

not sandboxing, but this should resolve most of the concerns about unsafe functions being available: 093834e

reopen if desired but the security problems should be mostly if not entirely gone

	if (blank_env) {
	lua_newtable(L);
	lua_setfenv(L, lua_gettop(L) - Args - 1);