Deprecate colstyle.m?

[Rik]

1/22/14

All,

The function colstyle() was added in 3.4.  As far as I can tell, it's
because certain plots in the Matlab toolbox specgraph used to use it.  But
Mathworks seems to have killed the function, and Octave uses an internal
function __pltopt__ to do something vaguely similar.  Is there a reason to
keep this for the 4.2 release or can it be deprecated at that time?

--Rik