Add rotate slice optimization.

Disabled until broadcast mapping is supported.
Make Broadcast support map over tiles.
Fixed the good_tile_shape bug.
Fixed bugs related to the good_tile_shape bug.
Merge pull request #89 from fegin/broadcast

Make Broadcast support map over tiles.
Merge pull request #88 from fegin/bugfixed

Fixed the good_tile_shape bug.
Merge branch 'master' of github.com:spartan-array/spartan
Merge pull request #90 from spartan-array/rotate-slice-map

Rotate slice map
Merge pull request #87 from MaggieQi/master

change rpc to fast cython implementation
Merge pull request #91 from MaggieQi/master

change condition to pthread_cond
prot node_type to traits
merge from cython
get rid of all the _members and some minor changes
Merge pull request #92 from EasonLiao/traits

Port from node_type to traits
Merge branch 'master' of github.com:spartan-array/spartan

Conflicts:
	spartan/expr/transpose.py