fminsearchbnd new

A minor improvement on the fminsearchbnd (bounded fminsearch) created by John D'Errico. Changes:

% Changes from fminsearchbnd:
Changes from fminsearchbnd:
1) in options structure, user may pass an 'output function' and 'plot function' to fminsearch.
Original fminsearchbnd handled the output function via a nested wrapper function. I have extended
this to the plot function too.
2) I have moved the 'intrafun' function and wrappers to be nested functions (INSIDE the
fminsearchbnd function), so they do not need to pass the params structure around (into
fminsearch) - but have access to it directly. This
maintains the integrity of the varargin, which the user may be passing thru fminsearch to their
optmization funciton (fminsearchbnd had passed the params structure to fminsearch, thus ruining any
varargin that the user passed in).
3) I have created a test example so the user can see not only how fminseachbnd works, but also how
the OutputFn and PrintFns functions work, which were heretofore poorly documented by MathWorks.