Get and display version info for ux, coi-services, other dependent projects

Versions are shown in a modal popup, triggered by clicking a link at the bottom of the sidebar.
![Screen shot 2013-01-21 at 3 50 33 PM](https://f.cloud.github.com/assets/228715/84369/7e935148-640c-11e2-813e-8775e92a3ebb.png)

Clicking "Version Info" results in:

![Screen shot 2013-01-21 at 3 50 47 PM](https://f.cloud.github.com/assets/228715/84370/86f4565c-640c-11e2-9b8e-e4606df5f0dd.png)



Also included is a commit that addresses some url building refactoring, including removing mutable object constructors in method signatures, which is a python no-no.