Feature request: allow configuration of file system operations

[Ontonator]

There are a few different cases in which I would like to override the default file system operations:

• For files that have been added to Subversion, I would like to override both mv and rm with svn mv and svn rm respectively.
• For all other locations, I would like to override the default rm operation with rip.

I imagine others would have their own cases in which they would wish to override the defaults, hence it would be nice if this were configurable.