Allow ignore=pattern definitions in .wakatime.conf to ignore files

Wakatime is forever reporting my emails as /tmp/mutt-blahblahblah and I personally don't care to be reminded how many and what number of emails I had to send so I added this to let me include ignore patterns in the config file (e.g. `ignore=/tmp/mutt-.*`).

As mentioned in the TODO comment the config parsing code is duplicated and should probably be merged into a single one but I didn't have time to do that yet and it seemed like a separate issue.

EDIT:  I have now restructured it to allow --ignore patterns on the command line and added some additional options to the config file that were available as command line options (namely --logfile and --verbose).  Now there is only one pass to parse the config file.  Options from the command line are given precedence over those in the config file, but the ignore patterns are merged.