Convert graphs to binary format

Squashed commit of the following:

commit 7968c7b239b7de27f3897c7a412dea2527b7b7a6
Author: Gabe Kopley <gabe@coshx.com>
Date:   Tue Apr 23 13:54:40 2013 -0700

    Cleanup

commit 5148ef08b5f2ae3e0124ca3d6b804fd737b1a544
Author: Gabe Kopley <gabe@coshx.com>
Date:   Tue Apr 23 13:51:00 2013 -0700

    Weights work also

commit e2c69ec31cfc1ff491b5b03a64d2fbc461125a29
Author: Gabe Kopley <gabe@coshx.com>
Date:   Tue Apr 23 11:54:14 2013 -0700

    Convert seems to work

commit 17a8d2381edc7fa5f4aa291f3a52071792f64271
Author: Gabe Kopley <gabe@coshx.com>
Date:   Mon Apr 22 16:01:54 2013 -0700

    Maybe works, can't depend on digest cause of different hash order iteration b/t ruby and C++

commit 14c0cdeec7fdb9742630ce897f70e4d4a1dd3d63
Author: Gabe Kopley <gabe@coshx.com>
Date:   Mon Apr 22 13:30:19 2013 -0700

    Convert WIP
Graph#to_binary_graph