Implement #47 - Default to 'All Frames' tab when no application frames are available.

![selection_004](https://f.cloud.github.com/assets/382538/1057696/b7f0bc76-1179-11e3-8ae6-baf5e7bd67a5.png)

This PR adds a check for the amount of Application Frames available, and if there are none, disables the "Application Frames" button, and falls back to the "All Frames" tab.

Cheers! :cat: (hi charlie!)