Enrolment

The following work was done make the work like it did under the old enrolment system.  For various reasons we add students to courses but do not remove them based on the ims data.  We let the faculty do the removal.  So the first thing I did was add the permissions and ui for doing this with.  Then last friday I got annoyed looking at the regex's and converted the plugin over to use simplexml.  It seems to run faster now.  I previously converted the plugin to pull from the web and now I made it handle both the web and filesystem.  My test cases were the included examples and my own 2.8 meg 95000 line ims file.

Add access.php to set pemissions

Allow pulling ims file via http(s) in addition to the filesystem.

Add edit and unenrolment functionality

Convert from using regex to simplexml to process ims file

This was written for 2.1 but I have done the patch against 2.2 as that is where the activity is. Since I was making the access and edit changes I figured I would deal the xml issue while I as at it. Solving one problem with a regex gives you two problems.