Remove executable bit from files that shouldn't be executable

Part of #1569
Separate dashboard templates from frontend templates

This allows us to use different CSS frameworks for frontend and dashboard.

Part of #1569
Separate frontend and dashboard CSS and JS

Things explicitly shared between frontend and dashboard, in base.html:
  * jQuery

Things referenced in both respective layout.html files so as to allow
for hassle-free implementor customization of frontend and dashboard
independently:
  * js/bootstrap/bootstrap.min.js
  * js/oscar/ui.js

Part of #1569
Add Bootstrap3

Part of #1569
Port frontend to bootstrap 3

Part of #1569
Use grid gutter padding for product pod price box

The the grid gutter padding was removed with .no-padding only on the main
catalogue browse page, leaving search results, recent products on detail
view and a number of other pages that have product pod lists in them with a
double padding.

Part of #1569
Make max width wider for large devices

Bootstrap 3 recognizes a class of widths >1170px "Large devices".

Suggestion by @itbabu.

Part of #1569
Adjust number of products per row for different viewport widths

Suggestion by @itbabu.

Part of #1569
Contain image within its container

Suggestion by @itbabu.

Part of #1569
Make sidebar wider for small widths so that the category tree fits

Suggestion by @itbabu

Part of #1569
Bootstrap3 uses danger in place of bootstrap2's error

Part of #1569
Regenerate CSS

Part of #1569