Organizing directories

Goals:

Code goes under isetools
Scripts (s_) go in scripts.
Tutorials (t_) go in tutorials
Validations (v_) go in validation/validationScripts

Subdirectory structure is parallel between isettools, scripts, tutorials, and validations.

Tutorials should be well-commented and published, and should illustrate how to do things.

Validations should store validation data and check stuff.  They will also be published and should be reasonably commented.  But they are allowed to be a bit more obscure than tutorials.

Scripts are project oriented code.  It is possible these should all move out of isetbio and into computationaleyebrain.

Some pruning of all of the stuff we have may be in order, but for right now just trying to get it organized in a manner that lets us chip away at that.

Signed-off-by: David Brainard <brainard@psych.upenn.edu>
Moved data to top level, out of isettools

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