Theme logic separation

First attempt at separating Lua/LuCI functions from HTML in theme template files. Should result in easier theme customization, since web designers will not need to deal with Lua in order to edit HTML/CSS.

To test:
Check setup wizard, non-admin (apps, license, about) pages, login, and admin pages for proper functionality and page render. Check both full size and small display sizes.

<!---
@huboard:{"order":33.34375,"custom_state":""}
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