Upgrade main Contexts for behat 3
Update browser sub contexts (class > traits)
Remove deprecated common sub contexts
Add ContentTypeGroup sub context (new standard)
Helpers now come in trait shape or static classes
Update Content managers

This required a separation of the old ObjectContexts that had the sentences merged with implementation
Now each one has its own job
ObjectManagers are the implementation part
and
ObjectContext are the sentences (behat) part
Clear traits and helpers
Drop sentences interfaces
Move ObjectManager::instance() to abstract Base class
Create a Gherkin specific helper
Refactor files strucutre/namespaces
Fix minor typo's and missing steps
Minor update to sentences
Add file headers and explanation
Update ObjectManagerInterface
Fix wrong method on interface
Update travis to reflect changes for behat 3
Fix typo on method name
Add 'I go to the homepage' sentence
Fix minor typos