Move HTML generation from course/lib.php to renderer

The course renderer has been created (class core_course_renderer in course/renderer.php)
but there are still a lot of functions in course/lib.php that output html directly. They must use renderer callbacks:

print_overview() - MDL-36967
print_recent_activity() - MDL-36968
print_section() - MDL-37085
print_section_add_menus() - MDL-37085
print_category_info() - MDL-37193
print_courses() - MDL-37009
print_course() - MDL-37009
print_my_moodle()- MDL-37009
print_course_search() - MDL-37009
print_remote_course() - MDL-37009
print_remote_host() - MDL-37009
make_editing_buttons() - MDL-37085
print_log()
print_mnet_log()

Also use renderers in php files in /course/ folder:
category.php
index.php
info.php (just one <br/>)
report.php ?
resources.php ?
scales.php ?
search.php