Modify to implement protocol correctly, by switching to TCPSocket

Previously this package used Net::Telnet. However Net::Telnet does
CR+LF => LF translations and requires other options to be set to
be binary safe.

As a result, passing binary data into beanstalkd would frequently
fail. Data containing telnet escapes would get mangled, and data
containing CR+LF would cause the client to believe the command
was finished.

The client complete ignored the number of bytes specified for the
responses that needs them.
Extra test cases for TCPSocket switch
[test/helper] require 'mocha'
[test/pool] fixes expectations
[connection] trailing white space
Cleanup telnet mentions
[connection] refactor #parse_response to be more explicit
More cleanup telnet mention
BUMP VERSION TO 0.3.0