Fix Homebrew uninstallation and move virtualenv/ to support folder

The last OMERO-homebrew-{stable,develop} jobs have been fail when calling
`bin/brew doctor` with a "Warning: You have uncommitted modifications to
Homebrew". This PR applies the uninstallation mechanism suggested in the
Homebrew installation script.
Additionally, a VENV_DIR variable is defined to extract virtualenv into a
proper support.
Add simple method to check if image was imported prior to FS
Merge pull request #1059 from snoopycrimecop/merge/develop/submodules

Update develop submodules
set the compression to high for big images (see #10759)
Merge pull request #1034 from sbesson/rebased/develop/homebrew_uninstall_hudson

Fix Homebrew uninstallation (rebased onto develop)
Merge pull request #1079 from jburel/fs-image

Add simple method to check if image was imported prior to FS
Merge pull request #1086 from jburel/rebased/develop/big-image-compression

set the compression to high for big images (see #10759) (rebased onto develop)
Update submodules