fixes #851 - display diff view on Puppet file content change

new version of ace editor, better diff colors, diff in report show page.
fixes #2147 - param classes with multiple matchers are evaluated incorrectly
[test] renamed wrong class name
Make sure we're not merging nil in to_json

Options argument might be nil. Therefore it fails when trying to call
{}.merge(options) (for example when recording examples with apipie).
Using Apipie versioning features