Sara Arjona a26cfe71d3 MDL-65809 upgrade: clean < 3.5.0 upgrade steps
This just deletes all the upgrade steps previous to 3.5.0. Some
small adjustments, like tweaking globals can also be applied
when needed.

Also includes an upgrade step to prevent upgrading from any
version < 2018051700 (v3.5.0) as anti-cheating measure.

Previous commits have removed/deprecated all the upgradelib functions
not used anymore in codebase. Deletion has been documented in corresponding
upgrade.txt files:

- upgrade_fix_block_instance_configuration()
- upgrade_theme_is_from_family(), upgrade_find_theme_location()
and linkcoursesectionsupgradescriptwasrun setting
- upgrade_block_positions
- upgrade_fix_config_auth_plugin_names()
 and upgrade_fix_config_auth_plugin_defaults()
- format_xxx_upgrade_remove_numsections(), format_xxx_upgrade_hide_extra_sections()
and format_xxx_upgrade_add_empty_sections()
- filter_mathjaxloader_upgrade_cdn_cloudflare()
and filter_mathjaxloader_upgrade_mathjaxconfig_equal()
- get_assignments_with_rescaled_null_grades()

These have been kept because continue being used by restore:

- \core\task\refresh_mod_calendar_events_task
2019-12-20 12:20:43 +01:00
..

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You should have received a copy of the GNU General Public License
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copyright 2009 Petr Skoda (http://skodak.org)
license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later


Page module
=============

Page module is a successor to original 'html' and 'text' type plugins of Resource module.


TODO:
 * implement portfolio support (MDL-20076)
 * new backup/restore and old restore migration (MDL-20077)