Caliburn -> Caliburn.Micro migration

Upgraded to Caliburn.Micro.

First commit is just namespace changes.

Second commit has code changes. Sticky bits are:
- The search bar uses DevExpress controls that weren't compatible with Caliburn Micro. Swapped from using actions to commands. See https://caliburnmicro.codeplex.com/discussions/218975
- Same for a hyperlink in MessageFlow/MessageActionPopup See http://caliburnmicro.codeplex.com/discussions/227316
- Rewrote most of AppBootstrapper

Third commit updates the tests.