CreateBranch creates a new branch with the given hash as the head, or the current HEAD hash if empty.

GetLocalBranchRefName returns the reference name of a given local branch.

GetRemoteBranchRefName returns the reference name of a given remote branch.

todo: should just replace everything or take an upstream delta.

ChartsQuarantineBranchName is the name of the "working" branch where the incoming changes are applied.

ChartsStagingBranchName is the name of the branch used to stage changes for user interaction / review.

RebaseBackupDir is the directory where the charts are backed up to.

AllowedDirectories is the list of directories that are allowed to be untracked in a repository wiuthout being considered dirty.

ChartValidateFunc is a function that verifies a chart using the provided filesystem.

PackageValidateFunc is a function that verifies a package using the provided filesystem.