Misc enhancements & fixes

* Timeout improved after intensive tests
* Log attribute set to public for debug purposes
* Ability to disable catch all testing (catchall_test)
* Timeout are now catched properly (flag email as valid) in case
to accept down in case to avoid false positive
* Better support for RSET, NOOP and QUIT on weird RFC
implementations
* Added catch to handle empty/non-response
Improved codes

* Added constant for codes 500, 502 and 503
* Replaced tabs with spaces
* expect() returns en Unexpected exception instead of
no response in case of empty response
Merge pull request #10 from kevin39/master

Misc enhancements & fixes:

- reduced some timeouts, added ability to skip catch-all testing, expect() tweaks..