* Simplify app code dealing with overrides
* env set will not mutate passed environment, filters out library configration for overrides
* app.Environment, app.Environments return merged views with overrides applied
* Test override environment merging
* remove redundant calls to mergedEnvironment
* Remove name parameter from AddEnvironment
* Fix override flag for merged environments

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