First architectural changes

General architectural changes:
* *Pubrules* version: `0.3.3` → `0.4.0`
* *Bootstrap* version: `3.1.0` → `3.2.0`
* *jQuery* version: `2.1.0` → `2.1.1`
* `index.html`:
  * Unified single vs. double quotation marks.
  * Fixed a couple of minor HTML errors.
  * Commented out *Bootstrap* default theme.

Next in this branch: tackle issues #22 and #25.