add a sanity check to see if messaging is enabled before outputting menu item

If messaging is disabled we shouldn't output the messaging option on the custom menu.

TODO: check if popup notification or jabber are configured or not
Check if popup messages are enabled

Add a check to see if the popup message output is enabled before outputting a link to messaging in the custom menu
Merge branch 'hide_msgnav_when_messaging_disabled' of github.com:thedannywahl/moodle-theme_elegance into hide_msgnav_when_messaging_disabled

Conflicts:
	renderers/core_renderer.php
strip merge message

lol, I still suck at git.
add missing braces

Close missing brace for nested if statement
proper field check

check the proper field value "enabled" to see if messaging is enabled - not if the record exists in the database.
Merge pull request #64 from thedannywahl/hide_msgnav_when_messaging_disabled

add a sanity check to see if messaging is enabled before outputting menu item