Re: Property values for boolean properties.

[Karl Fogel]
> How about the command-line client prints a warning if you set one of
> these properties to "off", "no", or "false"? That is, it does the
> propset, but also prints to stderr a message saying that this might
> not have the effect you want/expect.

Sounds good - but I think it should special-case value "" (the empty
string) as well. Either include that in the warning codepath, or jump
to propdel if you try to set a boolean to "". In fact, maybe propdel
if you try to set _any_ svn: property to the empty string.