Working on faster serialization.
Merge pull request #43 from fegin/master

Refine some test files.
* fix the bug in some test cases
Merge pull request #2 from MaggieQi/faster-serialization

Faster serialization
Merge pull request #45 from fegin/master

Add support for sparse arrays in make_from_numpy().
* add test cases for serialization
Merge branch 'MaggieQi-master'

Conflicts:
	spartan/rpc/common.py
Make dot expr as an Expr
Make dot expr as an Expr
Merge pull request #47 from fegin/master

Make from_npy as an independent function.
Merge branch 'master' into dot
Remove some redundent spaces