MDL-36017 Added default fields to format_legacy::course_format_options()

Fields coursedisplay, numsections, hiddensections are now the default fields for formats being converted from Moodle 2.3 or earlier
MDL-36017 Fields numsections, hiddensections and coursedisplay are now format-specific options

- Fields added to format_legacy as default course format options;
- Upgrade script copies fields values from table course to course_format_options;
- Fields removed from table course;
- Fields removed from edit course form;
- Since front-page course has a 'numsections' setting, format_site defines it as it's option;
- Removed accessing those fields in core code unless we know that format supports them and in this
  case instead of $course = $DB->get_record('course'); we use:
  $course = course_get_format($courseorid)->get_course(); This way all format-specific options
  are added to the $course object
MDL-36017 Course now may have format-specific options, numsections and hiddensections are among them
MDL-36017 IMS-CC export does not filter result by numsections because it is now optional
MDL-35769 Give more flexibility for course formats to extend course navigation

global_navigation::load_course_sections() now has more parameters and ensures
that current section and activity is loaded. This will allow course formats
to display hierarchical sections in navigation and have one callback for
overwriting whole course navigation
MDL-36317 Execute course format callback when course or module is set on page
MDL-33017 Show Currently viewed course in new node
Merge branch 'w42_MDL-35469_m24_geckover' of git://github.com/skodak/moodle
MDL-35768 MDL-36017 code style corrections
MDL-33766-master repository: Upgrade notes
MDL-36338 Usability: New Edit icons in SVG and PNG formats
MDL-34270 blocks: adding new add block capabilities
Merge branch 'MDL-34270_master' of https://github.com/markn86/moodle
MDL-36303 Calendar: remove html special chars from event link in calendar block
MDL-35349 paypal: Fixing return page so that it now declares page context
MDL-35998 get_site_info return current_language()
MDL-36025 qtype calculated: Fix handling of "-0"
MDL-36347 quiz: formchangechecker should not obstruct auto-submit.

When the quiz time limit runs out, the quiz should be submitted
automatically, withouth formchangechecker popping up a dialogue.
MDL-31847 theme_base: adds highlight colors to table rows
MDL-33017 navigation: added current course and simplified loading