Fix signature of check-milestone function
Document renaming of scc check-prs
Describe new filters introduced in scc 0.5.0
Document Homebrew formula upgrade to 5.0.0

- Remove the `--devel` option to install OMERO 5.0.0
- Simplify the environment variable configuration for Ice 3.5 (default)
- Add environment variable sentence for non-default Ice 3.3 and 3.4
merge develop -D org -I include -E exclude: PR 626 (Add new Squash tutorial and screenshots)
merge develop -D org -I include -E exclude: PR 681 (Document Homebrew formula upgrade to 5.0.0 (rebased onto develop))
merge develop -D org -I include -E exclude: PR 682 (Document scc 0.5.0 changes)