changes to graphics.cc and subplot.m

[Ben Abbott]

All,

I've just pushed two changesets ...

        http://hg.savannah.gnu.org/hgweb/octave/rev/350cad34b0f8

        http://hg.savannah.gnu.org/hgweb/octave/rev/942d892524b3

... which should fix several bugs in the tracker (I'll verify and close them on 
the next week).  I don't expect any regressions, but if anyone sees something 
unexpected please let me know.

I have some additional changes planned to clean up legend.m.

Ben