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
Fix links to Bio-Formats source code post-renaming

This commit should update the source code links to point at the new
formats-bsd, formats-gpl and formats-api folders of the Bio-Formats repository
change TeX Gyre font package so XeLaTeX can find it
Merge pull request #688 from sbesson/formats_bf_renaming

Fix links to Bio-Formats source code post-renaming
Merge pull request #689 from mtbc/tex-gyre

change TeX Gyre font package so XeLaTeX can find it (rebased)
Merge pull request #681 from sbesson/rebased/develop/homebrew_5.0.0

Document Homebrew formula upgrade to 5.0.0 (rebased onto develop)