Introduce StatusOptions.IncludeUnaltered
Introduce PathSpec for StatusOptions.

Conflicts:
	LibGit2Sharp.Tests/StatusFixture.cs
	LibGit2Sharp/RepositoryStatus.cs
	LibGit2Sharp/StatusOptions.cs
Introduce StatusOptions.DisablePathSpecMatch

Conflicts:
	LibGit2Sharp/RepositoryStatus.cs
	LibGit2Sharp/StatusOptions.cs