[MERGE] Add ls-shelf command

[Aaron Bentley]

John Arbash Meinel wrote:
> Martin Pool wrote:
>> Martin Pool has voted tweak.
>> Status is now: Conditionally approved
>> Comment:
>> I think 'shelve --list/-l' would be a bit more stylish, and avoid
>> growing the command list too much.  (I realize it's a grey area, since
>> we don't do 'shelve --unshelve'.)
> 
> We do have "tag --delete", and we are discussing at least whether we
> should have "branch --delete".
> 
> I'm probably in favor of "bzr shelve --list" as well, though not
> tremendously.

I'm somewhat against "shelve --list".  That completely changes the
behaviour of the command.  I didn't think listing shelved changes fit
nicely into either "shelve" or "unshelve".

Still, if that's what it takes to get the functionality, I'll do it, and
alias it to ls-shelf for myself.

Aaron