* baseApp.load() / baseApp.save() are override-aware
* app.read() / app.write() (schema.go) are not - they only serialize/deserialize app.yaml
* baseApp.load() / baseApp.save() now call app.read() / app.write() instead of duplicating serialization logic
* Removed isOverride flag from EnvironmentConfig, RegistryConfig
* Removed override logic from app.Load() - this is handled in baseApp.load() now
* env set command now respects the --override flag to indicate where to write changes

Closes #830

Signed-off-by: Oren Shomron <shomron@gmail.com>