MDL-2674 adding $cm->grouping reset if groupings not restored; removed info about groups included in backup - they are always included, and there will not be any global groups/groupings; merged from MOODLE_19_STABLE

MDL-2674 backup always backsup/restores groups regardless of user settings; remerged from MOODLE_19_STABLE

MDL-13847 gradebook backup/restore fixes, xhtml strict fixes, other minor fixes; merged from MOODLE_19_STABLE

Fixes bug MDL-2674, "backup always backsup/restores groups regardless of user settings" - restore group/grouping option.

MDL-12450 - Matching up roles on the restore settings form is broken - this is basically a complete rewrite of these two functions. Merged from MOODLE_19_STABLE.

There is something _weird_ about the table setup on this page
and I cannot figure it out. This change "fixes" it in that
FF stops complaining.

However, the fix looks very broken to me.

MDL-11234, if role definitions matches, restore role mapping should be allowed with or without role assign capabilities

added needsupdate flag into backup/restore, added a new switch for restore on/off for grade histories, fixed some NULL related warnings

Merged from MOODLE_18_STABLE

(some formats like main page, social..., haven't it and rolling dates
from 0 produces crazy dates. MDL-10125

Merged from MOODLE_18_STABLE

Fixes for some notices because of unitialized vars and elements that may not be present in older backup xml.

(bigger but enough smaller than the fullname field)

Credit goes to Josh Benner by finding it.

Removed Javascript language attribute tags and added CDATA