Update installer.rb tpl to use gems compatible with refinery2718
Update turbolinks
Fix welcome message for first user
Update versioning per Travis instructions.

Conflicts:
	.travis.yml
Upgraded generator_spec for cleaner example group declaration.

Conflicts:
	Gemfile
Renamed source control keep files.

This keeps in line with Rails since https://github.com/rails/rails/pull/7614.
Injected Refinery into routes agnostic of how the application is declared in the routes file.

Conflicts:
	core/lib/generators/refinery/cms/cms_generator.rb
Replaced File.open ... do with File.read/write.
Rename wysiwig to visual_editor https://github.com/refinery/refinerycms/commit/684a9bfcc39aa
Introduce ThumbnailDimensions model to simply Image.

Conflicts:
	images/app/models/refinery/image.rb
Added spec to prove user_plugins failure to update, per #2580