fixing public user documentation

fixing public user documentation
adding login link to the public access doc
formatting new text
Merge remote-tracking branch 'origin/dev_4_4' into rebased/dev_4_4/public_user

Conflicts:
	omero/sysadmins/unix/install-web.txt
Merge pull request #524 from aleksandra-tarkowska/rebased/dev_4_4/public_user

fixing public user documentation (rebased onto dev_4_4)
Marking up example links
Actually making links not checked
Adding note about non-existent links to readme
Making backslash actually show up!
Improving readme note
Further improvement
Merge pull request #529 from hflynn/rebased/dev_4_4/linkfix

Marking up example links (rebased onto dev_4_4)
Minor changes following review on devlop docs.
Remove references to the FORMATS-*-stable jobs

Since we are only exposing the model documentation for the develop branch,
these jobs have been deleted and should not be mentioned on the continous
integration section anymore.
Merge pull request #530 from sbesson/formats_stable_job

Remove references to the FORMATS-*-stable jobs
Merge pull request #532 from ximenesuk/testing-pytest-typos

Minor changes following review on devlop docs.