Feature/mac dmg
Created by: thibauthourlier
The main changes are:
- Use of MacPort 2.5.4
- Default Perl is default macport perl, 5.26
- Some perl modules are not tested as otherwise they are not installed even for a non critical failure, look in the CPAN YAML files
- Addition of a script to create the dmg file, otterlace/release/scripts/MacOS/create_otterlace_dmg.sh. Creating an image from scratch should take around one working day
- Manual changes should not be needed except to make sure that the correct branch is set and that the Git.pm module is correct.