method delegation in TextWithDash

I dont think that can work, since

    > set_xticklabels(['foo',...]) makes its own call to
    > set_text('foo').

ax.set_xticklabels calls ax.xaxis.set_ticklabels which creates a new
Formatter with

        self.set_major_formatter( FixedFormatter(ticklabels) )

ticklabels are kind of funny, and this is related to the question on
the user's list about setting the location of ticklabels. The
location and string are determined at draw time by the Locator and
Formatter class, which is why well-intentioned but naive attempts to
control their location and text directly often fail. One has to set
the locator and formatter, and this is highly configurable and
customizable. For the most part, I think it works fine.

The one use case brought up on the users list that the framework
doesn't address is the "centering" issue of ticklabels, trying to get
the labels centered between ticks. I'm mostly -1 on this, and I think
the major/minor hack I suggested can solve this use case fairly
cleanly, but I'm open to counter arguments. What might be nice,
however, is to add a padx, pady properties to text instances in
general or maybe just ticklabels in specific, that will shift their
horizontal and vertical position by a fixed amount in points.