**Release 0.2.0:**

* added genotyping-related sub-package "gt" (for now it just contains protobuf serialization stuff)

* added "io" sub-package with readers/writers for some bio file formats

* added "messages" sub-package with general-purpose protobuf modules

* added "seq/align" sub-package with tools for reading SAM files

* added a module for converting sequences to the nib format
