Fully working SP capnp with timing test for iostream capnp and old method.
Adds SP timing test to prototest.
Got SparseMatrix and SparseBinaryMatrix working with Cap'n Proto and
leveraged this from SP serialization.
Adds tests for new serialization.
Switch to absolute import paths for capnp.
Clean up after prototest tests.
remove unused variable from prototest
code review updates.
Removes double-reading of permanences in SP.
Merge pull request #248 from scottpurdy/capnp-spatial-pooler-2

Spatial pooler serialization ported to Cap'n Proto