FIX connection errors with P0 secure services

[amatmv]

Many changes have been made so far:

• Include raw http basic auth token in requests header to the service.
• Remove encoding declaration header to avoid errors.
• Return only the MensajeEnvioInformacionPS tag content.
• Temporal fix of the urrlib2s error that validates the SSL certificates of some web servers: https://stackoverflow.com/questions/27804710/python-urllib2-ssl-error/27826829#27826829

[coveralls]

Coverage decreased (-0.1%) to 76.111% when pulling e1d73d7 on disable_ssl_verification_tmp into 0d36a69 on master.