Modify default Homebrew installation directory to /usr/local
Use Homebrew recommended installation command and run brew doctor

This command also takes care of setting the permissions on the /usr/local/
folder so that we don't have to care about this. During initial clenaup,
remove contents of /usr/local without removing the folder (may not be
permitted).
Do not allow BREW_DIR to be overriden

Since using the default Homebrew installation command, we don't have the
choice of the installation directory anymore.
Clean Homebrew as suggested in the installation command
Test if git is already installed
Prepend /usr/local/bin to the path before running brew/doctor
Review test for #10347
cleaning
Add an extra test.
Fix hanging of diagnostics on Windows
Add extra test using pojo object.
Add extra test checking if original is loaded.

Check that the original file is loaded when
the exclude close is on.
Replace pixelsId by imageId to reduce number of calls.
Remove unused import.
No longer returned silently an OME-TIFF (see #8188)

Prepare the call so it is easier to merge to FS branch
Check for null proxies in ~CmdCallbackI
Rationalize Fixture handling in OmeroCpp tests

The handling of the client objects was unwieldy. Now
across the board Fixtures have access to a local root
instance regardless of login, and a single login is
activated on demand. The destructor of all Fixtures
cleanup any non-null omero::client_ptr objects. This
is intended to workaround any "too many open file"
issues.

NB: Also removes tabs on any change file.
Modify result handling of archived download

* if no archived, indicate to load as OME-TIFF
* if more than one image, create a zip.
merge dev_4_4 -D org -I include -E conflict -E needs-fixes -E broken: PR 708 (Handle the case of unloaded original file (see #10347))
merge dev_4_4 -D org -I include -E conflict -E needs-fixes -E broken: PR 711 (Modify default Homebrew installation directory to /usr/local)