MDL-41900 events Log handler failures
MDL-37973 gradebook Return a maxgrade of '-' if grade type is TEXT

Including tests for correct return from
grade_edit_tree_column_range->get_item_cell()

This commit includes some special code just for 2.4 in the test
related to a bug in assign.
MDL-41894 feedback: Remove unused code, which is generating warnings
MDL-41954 Fix the grade for assessment calculation in the Workshop module

In a pretty rare case of zero variance of received assessments, the "distance"
of the evaluated assessment from the referential ("best") one was not increased
regardless it's actual value. This led to higher grades for assessments in
certain situations (see the tracker for a particular example).
MDL-26408 enrol_imsenterprise: fix invalid component
MDL-41995 calendar: moved the location the page layout was set for the export page

This was done so that the blocks are shown when logged in and viewing this page.
MDL-33569 themes: Labels create extra margin below content.

Conflicts:

	theme/bootstrapbase/less/moodle/course.less
Merge branch 'MDL-41954-workshop-zero-variance_24' of git://github.com/mudrd8mz/moodle into MOODLE_24_STABLE
Merge branch 'MDL-26408-24' of git://github.com/danpoltawski/moodle into MOODLE_24_STABLE
Merge branch 'MDL-37973_m24' of https://github.com/merrill-oakland/moodle into MOODLE_24_STABLE
Merge branch 'MDL-41894-m24' of git://github.com/ankitagarwal/moodle into MOODLE_24_STABLE
Merge branch 'MDL-41900-m24' of git://github.com/micaherne/moodle into MOODLE_24_STABLE
Merge branch 'MDL-41995_m24' of https://github.com/markn86/moodle into MOODLE_24_STABLE
MDL-41828 mod: fixed navbar when adding modules to a course
MDL-31830 course: converted to course_get_url