Mac packaging from superproject

That was easier than I thought. Here are some modifications to have medinria packaged on mac with all plugins at the superproject level. The process would be the following : 

- make medinria-superproject
- make private plugins (visages and/or asclepios)
- in medinria-superproject there is now a PRIVATE_PLUGINS_DIRS variable, fill it like this : "path-to-visages-plugins-build;path-to-asclepios-plugins-build"
- then make package and you'll get medInria-2.0.2.dmg in your build dir that contains everything

Tell me what you think, especially does this ugly variable suit your needs on other platforms ?