Stub docs/pull command.
Assert on docs/revs.

Update documentation.
0.1.200
Assert on --raw and --long with docs/revs.
0.1.201
Assert on docs/revs with errors and --lenient.
0.1.202
Assert on docs/rm.
Assert on docs/rm error condition.
0.1.203
Assert on docs/rm with --lenient.
Support --strict in docs/rm.
0.1.204
Add direxists() helper.
0.1.205
Tidy docs/* commands.
Support listing remote documents in docs/ls.
Draft docs deconstruct() implementation.

Converts documents back to fileobjects prior to writing documents and
attachments in a pull command.
Support --flat in deconstruct logic.
Respect --force in docs/pull document write.