add from_url() classmethod to ConnectionPool and BlockingConnectionPool, add ability to parse UNIX domain socket URLs
* add redis.connection.parse_url()
  * moved code from StrictRedis.from_url() to here
  * add ability to parse UNIX domain socket URLs
  * return keyword args to pass to StrictRedis.__init__()
* StrictRedis.from_url() - call parse_url() to get keyword args
* add classmethod from_url() to ConnectionPool and BlockingConnectionPool
  * get keyword args from parse_url()
  * touch up keyword args from StrictRedis format for connection pool
* tests/test_connection_pool.py
  * add from_url() tests for ConnectionPool and BlockingConnectionPool
  * add from_url() tests for a single Redis client object
pep8 fixes
restore a feature that was inadvertently removed
* fixed parsing URLs without a scheme, e.g. "//localhost:6379"
Merge branch 'pr/436'

Conflicts:
	tests/test_connection_pool.py
cleanup ConnectionPool and BlockingConnectionPool.
remove debugging
Cleaned up URL parsing code, now returns ConnectionPool instances.

StrictRedis.from_url() now creations a connection pool instance and
passes that as the connection_pool argument to the client class.

Cleaned up the test suite for URL parsing and BlockingConnectionPool tests
work around python2.6's broken urlparse implementation