Add inserts the file with the given `path` into the source archive, returning a non-nil error value if it fails.

AppendablePath transforms the given path and also replaces colons with underscores to make it possible to append it to a base path on Windows.

LoadProjectLayout loads a project layout from the given file, returning an error if the file does not have the right format.

TransformPath applies the transformations specified by `SEMMLE_PATH_TRANSFORMER` (if any) to the given path.

ProjectLayout describes a very simple project layout rewriting paths starting with `from` to start with `to` instead.