Merge pull request #17 from iclab/TLS

TLS
exception handling for TLS wrapping, added option to disable TLS
disabled some unnecessary logs from client-side
Changed structure that dns records are stored in results
Added records_received to results
Removed debug print statement and renamed result variables
Improved error handling and logging
Added documentation and removed redundant code
Tcp test now strips hostname from url
Removed dysfunctional time api
Updated primitive specs
restructured results to conform with new database schema
added time_taken_seconds to results
Removed redundant code from both Centinel and Sirocco, removed all encryption except TLS
bumped up the version
fixed a bug in netlib
added url in results for all tests
fixed a bug after refactoring the protocol
Merge branch 'master' of https://github.com/iclab/centinel-iclab
Update README.md