Engine Manager: minor doxygen cleanups
Engine manager: Added IB_MANAGER_DEFAULT_MAX_ENGINES
Refactoring Lua Runtime Management out of modules/lua.c into modules/lua_runtime.c
Moving RuleExt "lua:..." support into lua_rules.c and lua_rules_private.h.
Updating author email address.
Moving Lua-implemented module code into lua_modules{.c,_private.h}.