Template -> Processor

Closes #681
Merge branch 'master' into 4.x

Conflicts:
	lib/sprockets.rb
	lib/sprockets/coffee_script_template.rb
	lib/sprockets/engines.rb
	lib/sprockets/legacy_tilt_processor.rb
	lib/sprockets/sass_cache_store.rb
	lib/sprockets/sass_functions.rb
	lib/sprockets/sass_importer.rb
	lib/sprockets/sass_template.rb
	test/test_engines.rb