Update www/moodle to version 2.0.2

Update www/moodle to version 2.0.2

Mainly taken from PR pkg/44195 from maintainer Wen Heping.
Ok'd by maintainer.

pkgsrc changes:
- fix a couple hardcoded paths.

Upstream changes:

Many, many changes, too many to list here.
Includes a bunch of security fixes.

Please check:
http://docs.moodle.org/en/Moodle_1.9.10_release_notes
http://docs.moodle.org/en/Moodle_1.9.11_release_notes
http://docs.moodle.org/en/Moodle_2.0_release_notes
http://docs.moodle.org/en/Moodle_2.0.1_release_notes
http://docs.moodle.org/en/Moodle_2.0.2_release_notes

for the full list of changes.