Fix ChefDK Apps for Windows

Need to rebase and clean up a bit.

Fixes the following:
* Use the correct separator for the PATH environment variable for gem and bundle installs to install gems to the embedded ruby/gems (should we up-factor into omnibus?)
* Update software dependencies to be platform-sepecific where appropriate (this makes some software definitions depend on other definitions that are in omnibus-chef, should we move them?)
* Update the CA bundle's md5