add whitespace between tabs

It was getting hard to read.
use new ruby 1.9.3 syntax

An attempt to shorten the lines…
add missing tabs
remove parenthesis for consistency
move tab arrays into backend configuration model via constants

This one is a really cool one because that means that if you’re using a
spree extension and you want to make a tab active, you don’t have to
overwrite the _tabs file. All you have to do is add to the constants
:D. This is awesome.
remove unneeded partial option
render the product sub menu for new taxonomies

Found it weird it wasn’t loading for the new page. Here it is.