modules/lua_runtime.c: Moving global constant definitions so they are available when Lua modules are *re*loaded.
modules/lua_runtime.c: Bug fix - renaming variables that were blindly copied.
Point the default module base path at libexec, not lib.
predicate: Add predicate lua file to EXTRA_DIST.
build/common.mk: Modules install into libexec. Set the default search path.