#199 First name initials support for bibtex key generator

[Simon Rutishauser]

As support for my preferred bibtex key scheme (first author first name initial - first author last name - year) was not available in jabref, I have implemented the missing piece - getting the first author first name initial.

This patch adds the patterns [authForeIni], [authorLastForeIni], [edtrForeIni] and [editorLastForeIni] to extract the inital of the first/last author/editor respectively.

[Simon Rutishauser]

.. and the documentation

[Oliver Kopp]

Added to the master branch.