[MERGE] Initial support for marking bugs as fixed using bzr

[Ian Clatworthy]

Aaron Bentley wrote:
> ListOption is IMHO unwelcome.  I've put a lot of effort into making sure
> our options play nicely with aliases.  Every option type we support
> allows us to override aliases.  Boolean options provide an inverse
> option.  Value options allow another value to be specified, which
> overrides the previous one.  RegistryOptions allow another value to be
> specified, which overrides the previous one.
>
> ListOption does not provide a way for us to override it, if set from an
> alias.  There is no way to clear the list partway through and start
> over, and Jonathan hasn't even discussed it.
>
> Until we've resolved this, I am against putting ListOption in.
>
>   
I strongly agree with the need to allow list options to be reset to 
empty. One convention I've seen and used in the past is to allow '-' to 
mean reset. So using the pending -x option to selftest as an example, a 
user could have an alias of selftest=selftest -x paramiko (say) to 
always ignore those tests.

To override the alias so that those tests are run:

  bzr selftest -x- ...

Of course, this break downs when '-' itself is a legitimate list option. 
I've never seen a real life case of when that has happened though.

Ian C.