Merge pull request #3 from spartan-array/master

merge from the spartan-array:master
* add svm into examples
* add np.norm, np.diag, np.square, inc_vec, np.multiply ... support in buildins
* add test_serialization for local serialization test
Merge branch 'master' of github.com:spartan-array/spartan
remove assert dep is not list or dict
* add some documents on the svm and builtins
change svm.train and svm.new_train to svm.fit in test_svm
* remove register_blobs, get_worker_scores, get_worker_for_reload from
 blob_ctx and core
* change the array reference in master to weakref
get rid of inc_vec and _inc_mapper
Merge pull request #65 from MaggieQi/master

add svm example and some numpy function support