Add OAuth2 authenticator with initializer
Add authenticator default initialization test
Add error defines

Includes minor generated project file changes.
Add initial authentication with password grant_type

Include error handling, logging, and credentials
serializing.

Also add networking-related Foundation class
extensions.
Abstract out base test case class and refactor

Add additional properties for authenticator tests.
Add client authenticated initialization test

Allow the apiKey property to be writeable.
Add client Foundation class extensions test case
Merge pull request #4 from 3dna/peng/add-authenticator

Add authenticator for client