Replace all the addslashes with parameterised queries, and attempt to spot anywhere else that failed to escape queries properly

Removing the SUCS Blogs system and Planet. Security flaws, not used, old code. http://lists.sucs.org/pipermail/devel/2015-January/000103.html

Security. Menu items that have a non null permission value in the menu table will now only be visiable to people with that permission, unlike before where it kinda half worked and everybody could see everything.

...that prevented sensible error message being displayed if you try and signup a new member who has already completed the signup process

Similar fixes need to be handled in the susignup component

Allows staff to start sign up process for students who have paid but not yet signed up, including those who don't have their SU transaction ID.

Should coexist peacefully with existing signup system and the new SU signup component