Pulp

1. determine a list of "managed files" from the yaml config. Managed files should have a comment stating that plugin writers should not manually edit these files.
2. implement `update`, which clobbers all managed files
3. add a yaml field "skip_update_files" which allows the plugin author to skip managed files, if they must edit them.
4. implement --file-path option, which clobbers any file, managed or not. This can be used to create new bootstrap files that have been added since the plugin creation, or replacing files that have changed dramatically.