added support for idnumbers to the create and list course commands
made the listing of idnumber in the course list function an option
Added command to enable self enrolment on a course
Edited user create command to allow an external authentication plugin (e.g. ldap) to be specified
Modified user create script to accept idnumbers
Edited user list command so it can deal with sorting and display idnumbers if desired
Merge branch 'local_upstream' into extraoptions
Merge pull request #13 from bbusschots-nuim/extraoptions

Added Extra Options & Functionality