Issue #1 fix

* improved regular expression (keyword must be preceded by whitespace
  or beginning of the line, added some restrictions to variants of the
  keyword, ...)
* added UTF-8 support
Coffee regex improvements

* end of the line and other terminator characters added
* fixed terminator characters escaping
* removed illegal variants of the word 'kafe'
* no longer it reacts to empty message :)
Merge pull request #2 from incik/master

Issue #1 fix