add cholesky matrix decomposition
Merge branch 'master' of github.com:spartan-array/spartan

Conflicts:
	spartan/examples/cholesky.py
	spartan/expr/region_map.py
	tests/test_cholesky.py
change pthread_cond_wait to pthread_cond_timedwait to allow CTRL-C
update the test_cholesky
Merge branch 'master' of github.com:spartan-array/spartan
Merge branch 'master' of github.com:MaggieQi/spartan
add lda application
Merge pull request #105 from MaggieQi/master

Add LDA topic model to example