Add first callouts (WIP)

Adds callouts:

* imported via `callouts.tsv`
* localized in `data.en.yml`
* visually configured using `callout.qtip_config`, merged into [qtip2](http://qtip2.com/options), allowing for offsets, differing directions, removal of "tip", etc.
* only shown once per session, keyed by `callout.localization_id`
* close when you click their target element or the X
* show up underneath any modals

Also:

* removed unused `cdo.events` jquery event bus

![image](https://cloud.githubusercontent.com/assets/206973/2619778/222506aa-bc34-11e3-81ca-4a83455a0ef2.png)

![image](https://cloud.githubusercontent.com/assets/206973/2619786/3e62ec74-bc34-11e3-90c1-a0eb2aa3779d.png)

![image](https://cloud.githubusercontent.com/assets/206973/2619791/4a8d548a-bc34-11e3-9f81-f46c1c28a95e.png)

![image](https://cloud.githubusercontent.com/assets/206973/2619792/579fc68a-bc34-11e3-80dc-17823e6fa4f5.png)

![image](https://cloud.githubusercontent.com/assets/206973/2619798/66128d9c-bc34-11e3-9331-987b3a5bbea1.png)

![image](https://cloud.githubusercontent.com/assets/206973/2619805/97fa32ba-bc34-11e3-8141-63c408f3f627.png)