[TASK] Switch to renamed Services from Flux
[TASK] Simplify PageConfigurationProvider by using new Flux Service
[TASK] Adjust PageConfigurationProvider resolve call to new Flux logic
[TASK] Implement getExtensionKey in PageConfigurationProvider

This allows the ConfigurationProvider to read the extensionKey as specified either in TypoScript or automatically due to having registered the collection's extension key in PHP.
[TASK] Use Flux Service to get native View setup
[TASK] Add native extension key to setup if not already defined
[BUGFIX] Check for presence of error page template before rendering it
[BUGFIX] Remove method duplicated by merge
Merge pull request #34 from NamelessCoder/serviceunification

[TASK] Switch to renamed Flux Service