move licence to submodule
skip non-js files whenever loding  plug-ins(initializers, actions and tasks).
public git for licence
Merge pull request #151 from jacobbubu/master

Avoiding non-js files been loading in initializers, actions and tasks folder.
Add expireTime extension support when loading cache item and a relative test case
Could reset expireTime when loading cache item
Merge pull request #157 from jacobbubu/master

Could reset expireTime when loading a cached item
brining in cache and loaded updates form master