Create installer packages

[rsjbailey]

Create installer packages for Windows and macOS

(comment 1) I briefly looked at this on the macOS side yesterday. To create a package with a postinstall script (in order to install to the correct location then disable gatekeeper for the installed plugins) you'd need to use pkgbuild/productbuild - the productbuild CPack generator does this in theory, but in practice created a package which did nothing. It's probably easier to just write a script to build the package ourselves than to try and debug CPack. I think the easiest way might be to build component packages with pkgbuild for each project (extension, plugins) then combine them using productbuild.

(comment 2) Have you also considered using http://s.sudre.free.fr/Software/Packages/about.html ?

From gitlab issue 116

[rsjbailey]

see also #8