Removed usages of deprecated context functions
CONTRIB-4301 - Added modification protection to the default certificate types
Fixed errors in deprecatedlib.php
Check that the function exists rather than relying on the Moodle version
Fix deprecated function use in index.php.
Merge pull request #28 from timhunt/master

Fix deprecated function use in index.php.
Merge branch 'master' into MOODLE_25_STABLE