`tag --seal' broken

Hi,

`tag --seal' does nothing special, i.e., it doesn't create a `version-0'
patch level.  It seems that this problem has been around for some time
now [0].

I had a quick look at `cmd-tag.c' and `cmd-commit.c' and couldn't find a
reason why one would work and not the other.  So that's an open issue.
:-)

Thanks,
Ludovic.

[0] http://permalink.gmane.org/gmane.comp.version-control.arch.user/27231