enable deploying nagios plugins in pacemaker clusters

In order to be able to use a nagios plugin in the pacemaker cluster, it must be able to produce so-called meta-data, i.e. documentation as XML structured document. Content-wise, it is more or less like what --help produces, just with XML scaffolding. These patches add support for printing both help page and the XML meta-data from the same source (a set of C structs).

Already opened at SF:

http://sourceforge.net/tracker/?func=detail&aid=3589394&group_id=29880&atid=397600

Supersedes pull request https://github.com/nagios-plugins/nagios-plugins/pull/35