* renamed Preferences to "My report preferences"
* renamed Site defaults to "Report defaults"
* rename Change site defaults to "Change report defaults"
* reintroduced Inherit option to Grader preferences - Nicolas was right, it is not possible to implement preference overrides without it with our current get_pref inplementation
* new separate option in plugin selector "Course settings"
* moved displaytype, decimals and aggregation position to "Course settings"
* created new table grade_settings + related functions grade_get/set_preference()
* user report now uses grade_seq class instead of grade_item::fetch_all(); added preloading of grade items into grade_grade instances
* other minor bugfixing/cleanup/improvements
Please note that the Grader report preferences and its defaults must be resaved again - sorry.
MDL-11527 fixed warning from $CFG->defaultuserroleid when installing and upgrading
+ removed reusing of previous contexts in has_capability() and get_context_instance() because it was hiding critical errors when context was false, not specified, etc.
+ tweaked roles defaults - faster and defaults are applied when roles exist
+ SYSCONTEXTID may be specified in config.php to eliminate 1 db query
+ static context cache is now reset after rebuilding of context paths
+ path field in context table is now nullable - pg compatibility requirement
+ other minor fixes
MDL-11566 only site shortname, fullname and desc are required/displayed during installation
MDL-11567 fixed upgradesettings redirects if error in settings
MDL-11143 defaultfrontpageroleid moved to Frontpage settings page (easier to find), speedup
* in_null for decimals defaults checks
* store letter settings only in database - no cfg settings
* separate configuration page for letters only - pluginselector+admin tree
* new capability to manage grade letters - similar to scales and outcomes
* added grade_letters db index
* grade letters related minor bugfixing
added new favoutcomes plugin settings page - to be used later, this replaces the grade_outcomes_grades table
admin settings - outcomes and scales both have settings page now
Correct role capability requirements had not been included, so menu
was not displayed for roles with only category update and/or bacup
selected (assigned at site level)
Merged from STABLE_18
