Support DSA signatures
Merge pull request #36 from Fuzion24/master

Support DSA signatures
Fix fake type descriptors
fix extra space
Some fixes
Merge pull request #37 from google/fix_fake_type_descriptors

Fix fake type descriptors
Merge pull request #38 from google/temp1

fix extra space
Remove unnecessary parenthesis from dictionary tuple indexes
Merge pull request #39 from google/remove_tuple_index_parens

Remove unnecessary parenthesis from dictionary tuple indexes
Move some methods out of Graph
Fix an issue with some loops