Merge branch 'release/1.2.1' into develop
Bumping jstree z-indexes for "Move page" thickbox.

Current values were not high enough to rise above #TB_window / #TB_overlay values set in r27532.
Merge branch 'feature/3.9-compat' into develop
Version bump to 1.2.2
read me updates
Merge branch 'release/1.2.2'