Ignore locally compiled ReadMultichannelEXR mex file.

I think this is the right thing to do.

Signed-off-by: David Brainard <brainard@psych.upenn.edu>
Script to test whether RTB is working right after installation.

Also initializes the toolbox.

This is a work in progress, since the path names may change, and because I didn't debug it after my modifications.

Signed-off-by: David Brainard <brainard@psych.upenn.edu>