coursecat: Attempt to use session cache
Revert "coursecat: Attempt to use session cache"

This reverts commit db8596bc52a572e33203a85114204af3b88db343.
MDL-37009 Use renderer in print_remote_course(), print_remote_host()
MDL-37009 functions responsible for printing courses lists use renderers

- Functions print_course_search(), print_course(), print_my_moodle() are completely moved to renderers and deprecated
- Function print_courses() now call renderer to produce output
- Added function course_get_coursecontacts() retrieving contacts for particular course
MDL-37009 Moved print_xxx functions to deprecatedlib

Deprecated functions code is moved from course/lib.php to lib/deprecatedlib.php:
print_course(), print_course_search(), print_remote_course(), print_remote_host(),
print_my_moodle()
MDL-37009: added class coursecat_renderable, added render(), altered course/index.php and course/category.php
MDL-37009 first attempt for frontpage rendering
MDL-37009 retrieive courses list in category