Revert "Use monodoc.dll from dependencies, drop stale MonoLibraries installer."

This reverts commit fa3b25402562fd1c45b5ff131e34373a61001ba6.
[windows] Don't copy obsolete Mono.Addins.*
[windows] Copy monodoc.dll from dependencies
Remove unsupported help items, add unity help links
[windows] Copy dependencies in a better way
Merge pull request #25 from Unity-Technologies/unity-staging

Build script fixes