Move finders on Page to separate class.
Create instance method for with_globalize in PageFinder.
Separate out some methods for with_globalize in PageFinder.
PageFinder: add PageFinderBySlug class to wrap this logic.
Add PageFinderByPath class.
Include conditions for PageFinder.by_slug call
Pull PageFinderByPathOrId out to separate class.
Add PageFinderByTitle class.
Remove comments duplicated from Page.
Make with_globalize the default behaviour for PageFinder.
PageFinder: Remove passed in parameters from with_globalize
PageFinder: remove duplicate find methods, as the parent class takes care of this.
PageFinder: add separate finding classes for scoped and unscoped slugs.
PageFinder: separate out methods for finding by scoped paths.
PageFinder: Stop overloading variable names.
PageFinder: access all variables via private attr_accessors (ht: @ugisozols)
Added Gitter to README.md

[CI skip]
Added Gitter webhook for CI.
Revise images controller for compatibility with current Dragonfly.

This code was trying to rescue
Dragonfly::FunctionManager::UnableToHandle, which has been removed from
the current version of Dragonfly.
Fix a regexp which prevented the page's id to be correctly parsed.