Fipy migration

Major changes to use Github tokens, assign the correct ticket reporter and convert the Trac markup to Github markdown. The changes include:

 - `Translator` class for text conversion with regular expressions

 - update documentation for token usage

 - update documentation for Trac to Github markup conversion

 - replace users and passwords with tokens

 - `_getConfigOption` takes a Boolean option

 - tickets to issues map is created so that `ticket:XX` is converted to `issue #YY` syntax

 - tickets are uploaded to Github as the reporter from Trac. A token is required for every reporter otherwise the default token is uses. If tokens can be gathered the tickets are then reported by the correct user on Github

 - the Github issue has a live link back to the Trac ticket assuming it is active