Merge file annotation writing examples into annotation section

- Improve readability of the annotation writing subsection
- Merge Updating file annotation into Writing annotations
Improve description of getImages() by container signature
Homogeneize comments across the MATLAB documentation page
Minor fixes
Remove thumbnail methods from the MATLAB documentation page
Additional fixes suggested by @jburel
Improve description of CLI usage as a client
Extend scope of introductory sentence for the CLI
Removing final ref to logging in as root
Merge pull request #571 from sbesson/rebased/dev_4_4/11681_tobytearray

Document latest OMERO.matlab functions (rebased onto dev_4_4)
Merge pull request #587 from sbesson/rebased/dev_4_4/cli_docs

Improve description of CLI usage as a client (rebased onto dev_4_4)
Merge pull request #588 from hflynn/va_update

Removing final ref to logging in as root
Merge branch 'dev_4_4' of github.com:openmicroscopy/ome-documentation into dev_4_4