Support for manual QA routine

[atliSig]

We want to incorporate a a way for users to manually perform QA on samples.
Basic workflow:

1. From the main screen, the user selects to starts manual QA
2. The user selects a collection to perform QA on
3. LOBE selects a fixed amount of recordings from the collections that have not yet been checked
4. The user is presented with a recording one-by-one. The user should be able to:
   • Listen to the recording
   • View the waveform
   • Trim the waveform
   • Indicate if the spoken utterance does not correspond with the text
   • Indicate if amplitude is too low
   • Indicate if amplitude is too high

The Recording DB object should have a Recording.checked attribute to indicate whether the recording has been manually checked or not. The Collection list view should indicate the check progress.

[atliSig]

See this project and this branch for updates.