Fixing up some of the hybrid app creation

Fixing some discrepancies in the hybrid app creation flow:

- `config.outputdir` was not being checked for needing a default value, abs path resolution
- Made process exit codes unique
- Checked for the existence of the Cordova CLI client.
- Removed the Cordova npm requirement from the package; we rely on the Cordova CLI client to be installed and on the user's path.  Consuming the underlying node interface (i.e. having/utilizing a package dependency) is not very clean, and would seem to break the Cordova project's encapsulation expectations.
- Fixed some config issues.

TODO: Still need to fix up and update some of the binaries and post-install references.

We should make a similar change in forcedroid.js (removing the dependency on cordova and check for cordova cli)