Add rename/mv command.
This is the logical equivalent of copy and remove, and is in fact
implemented as such. It doesn't use the remove command directly.
adding foo
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
1 files, 1 changesets, 1 total revisions
requesting all changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
1 files, 1 changesets, 1 total revisions
foo
2ed2a3912a0b24502043eae84ee4b279c18b90dd 644 foo
pulling from http://localhost:20059/
searching for changes
no changes found
killed!