WIP snapshot (renamed: open_client => connect_rpc; start_server => serve_rpc)
a bit of progress
pipeline & pubsub stubs added
Merge branch 'master' into rpc_module_to_package

Conflicts:
	aiozmq/rpc/rpc.py
	tests/rpc_translators_test.py
rpc package structure refactored
basic pipeline implementation (without tests)
simple pipeline test added
rpc examples fixed
rpc docs updated: renames start_server => serve_rpc; open_client => connect_rpc
tests for aiozmq.rpc.pipeline
msgpack version check added
basic pubsub implementation
Change version to 0.1.0a
Refactor the doc, add example for RPC exception translator.
Document version and version_info
Rename low-level to core.
Update the docs
Add example
Add example for dicts as Handler structure.
Add example for subhandlers of AttrHandler