Add Move support.

This commit adds the Move, MoveAsync, MoveMinConf, MoveMinConfAsync,
MoveComment, and MoveCommentAsync functions for issuing the "move" RPC
with various optional parameters.

Closes #16.
IMPORT PATH MODIFICATION CHANGESET
----------------------------------

Please use this changeset as the first one on top of the conformal codebase.
Note that if there are new imports, they need to be changed as part of this
changeset. In general, use "git rebase" on github.com/conformal's version
and apply this changeset first.