lib/lingo/attendee/sequencer.rb: Allow regular expression patterns.

Only simple regular expressions with fixed length currently supported.
lib/lingo/attendee/sequencer.rb: Substitute matching pattern in format string (0).
ChangeLog: Updated.
README: Link to GitHub releases instead of tags.

https://github.com/blog/1547-release-your-software
lib/lingo/attendee/sequencer.rb: Allow arbitrary regular expression patterns.

The only restriction now is that the regexp must conatin any word class that is to be matched.
Specify license in GemSpec. (Closes #13)