Update seajs-flush.js

减少内存泄漏
Update seajs-flush.js

已经缓存过的mod不再缓存，fixed https://github.com/seajs/seajs-flush/issues/2
Unique Uris 

将deps里面相同的uri去重
Merge pull request #5 from lianqin7/master

Fix issues #2