Added license disclaimer to mock test files.
Added tests for com.podio.sdk.domian package.
Fixed bugs (found by test cases).
Extracted the Status enum to a separate class.

The Status enum is used both in Organization and Application, hence, it makes
sense to have it in a separate, top level class.
Introduced the Organization Role and Type enums (instead of strings).
Introduced the Field Status enum.

Observe that this isn't the same Status as the Organization and Application
domain objects use.
Removed ALL noise in the com.podio.sdk.domain.field package.
Introduced the Eclipse code formatting settings to the project.