This commit makes the following improvements to core page resolverss:
* allows for mixed case naming (course, Course, etc.)
* allows fields other than the idnumber to be specified:
** course: idnumber, shortname, fullname
** course category: idnumber, name
Whilst some of these fields are not unique, they will typically be
unique in most test scenarios. Where they are not then the idnumber
should be used in preference.
730d6cb94e