add oneof according to protobuf 2.6.0
Merge pull request #7 from AoJ/oneof

add oneof according to protobuf 2.6.0
1.4.0
Filter using boolean instead of extra trim passes
Merge pull request #8 from natevw/patch-1

Filter using boolean instead of extra trim passes
1.4.1
Merge pull request #4 from mafintosh/master

update