Add --shallow and --remote descriptions to the scc-scripts page
Add section about scc update-submodules command
Add section about scc unrebased-prs command
Improve usage of versionadded/versionchanged markup for 0.3.10

Add note about the rebased-to/from comments in scc rebase section
Correction from Will
Further clarification
merge dev_4_4 -D org -I include -E exclude: PR 470 (OMERO.scripts docs)
merge dev_4_4 -D org -I include -E exclude: PR 472 (Scc 0.3.10)