Merge pull request #81 from pauljz/master

Fix crashes in init prompts.
Updated to use a ScriptHost, updated DLLs for mono support for ScriptHost
Merge branch 'master' of https://github.com/pvcbuild/pvc
Added AppVeyor badge to README
Fix for regression with pvc-packages/pvc-project.json
Merge branch 'master' of https://github.com/pvcbuild/pvc.git
Major rework of depedency graph, circular dependency exceptions