BaseKite: allow setting the api after init or re-defining the api later
BaseKite: allow setting the api after init or re-defining the api later

This PR is a pre-sequel of https://github.com/koding/kite.js/pull/78
this time for BaseKite. Even though this breaks the immutability of api
it's allowing us to customize and extend Kite for other purposes.

Since current api immutability was in theory we can take this as gain :)

koding/kite.js