Update to 2.5

Upstream changelog is too long, please visit:
http://docs.moodle.org/dev/Moodle_2.5_release_notes
Updated www/moodle to 2.5
Update to 2.58

Upstream changes:
2.58 Thu May 23 09:04:37 2013
	- support PUREPERL_ONLY install option. (rt#84876)
	   (PERL_ONLY and NO_XS are not yet removed)
	- stop installing JSON::XS automatically on Perl 5.18
Updated converters/p5-JSON to 2.58