New Stack Template Selection w Popup Previews

When creating a new Stack, this allows you to preview what a Stack Template will look like before You create it by popping up a preview.
Stack Template System only includes publishd posts

When creating a Stack template Array, we only want Bricks that are published - no drafts or other
Default Template Code
Stacks Directory now points to Mint Plugins
Stack Background options are now in a showhider
Wording changes for stack sizes

Also removed <br /> tags from titles. That was silly...