fix(import): import is self-contained
fix(import): import is self-contained

Recently, when I used `import`, I made several mistakes.  This was in
part out of assumptions of how I thought it worked.  This changes import
to work like how I at least expect.

Import does:
- `cobalt clean`
- `cobalt build`
- and imports `destination` into the specified branch

Because of this extra processing, `cobalt build -i` has been removed.

Fixes #394.

BREAKING CHANGE: `cobalt build -i` no longer works.  Instead use `cobalt
import`.

cobalt-org/cobalt.rs,cobalt-org/cobalt.rs,cobalt-org/cobalt.rs,cobalt-org/cobalt.rs