The history of the task system changes is at
https://github.com/shana/task-system (8b3880cd69)

Also get rid of the separate NPath provider for cleaner code

This reverts commit 2eb64715.

This reverts commit 1badfbb2.

Add the simple api client from GHfVS, add credential management stubs per platform, add octokit and TPL 3.5 ports.
Remove CredentialManagement for now, it blows up on Mono (likely due to marshaling), so needs testing first.

The root solution loads the projects inside the src folder and subfolders, and
the GitHub.Unity project puts its output DLLS in the unity\TestProject folder,
which serves as a Unity test project for the compiled DLLs. If we need to debug
the code in Unity, the src\UnityExtension folder is also a Unity project, and
Unity compiles the sources files in it, so everything should magically work.

ignore rules for Unity and non-Unity projects are mutually exclusive
(csproj files being ignored, DLLs allowed, .meta files being included in
Unity projects), so we need to keep the Unity projects in a separate tree from
the rest of the .net projects in order to easily have gitignore rules that work
for both

# Conflicts:
#	src/IOTests/Program.cs