Dependency/OS PreReq Checker Integration

[kuszewski]

Packages requiring specific software to be installed no the host machine should have a clear place in the Module where those dependencies can be easily described and ZPM should check those pre-requisites.

For example, I have a package that requires Python be installed on the IRIS server (say I'm using embedded python or the python gateway). I'd like to make sure that it's installed before installing the package.

[isc-tleavitt]

Use case other than Python version (#874): Java

So we'll say this one is about Java.