Rework storage keys
Watcher for the src files
Conditional segmentation and conversion use cases

- Should not segment user if test can't be run
- Should be able to make the test complete
Introduced main.js interface
Watchr now watches src *and* tests
Spec tidy
Force the user in to a variant
Validate the test profile id

This negates the need to sanitise it when forming the local storage key.
Don't segment a user in to an expired test