Newsflow Activity classes Cleanup/Revamp

Tabs to Spaces
Removed ability to instantiate Newflow class outside of the singleton
Changed methods to always have a return type or throw an exception
Fixed Exception namespacing
Removed references to deprecated Loader class
PHPDocs
Changed Static functions to no longer be static in many places, now requiring the singleton to be called, in order to access what were previously static functions
Added properties to classes for IDE help
Changed path's to use rawurlencode in appropriate locations