Misc changes

I made some improvements and changes to suit my needs. You might be interested in incorporating some/all of them...

* Removed external dependency on graypy
* Added support for GELF over TCP
* Combined the scripts into one
* Parse the timestamp so that old log files can be imported with their correct timestamp
* Added tests

Cheers,
Luke
Graylog2-server does not accept it. It has to be formated as a string with precision of 3 (???), so replace by : 
        record['timestamp'] = "{0:.3f}".format(parse_timestamp(record['timestamp']))