Made record router smart enough to figure out collection links even if not given a full record driver object.

Made record router a service rather than a static class to enable dependency injection and easier overriding.

Set up links to collection view rather than record view for appropriate records when collections are enabled.

Revised Solr Tree Data Source to use record drivers instead of direct array access to Solr response.

Created collection controller; for starters, just an extension of AbstractRecord with a few minor changes and some cloned Solr Record templates.

Resolving VUFIND-590: email now requires authentication by default (to deter spammers), but anonymous emailing can be enabled via config.ini.

Treat account registration as non-AJAX form to prevent weird workflow issues (submitting subsequent forms to account registration endpoint instead of appropriate targets).

Removing VUFIND-160 workaround now that it is no longer needed (thanks to VUFIND-715 Yaml library improvements).

- Using version 2.1.4 of the Symfony/Yaml component.
- This allows more standards-compliant YAML parsing.

Resolving VUFIND-712 (Inconsistent YAML syntax for search specs QueryFields) and fixing use of escaped slashes in CallNumber munge rules.

* VuFind/Config/Reader/CacheDecorator.php (fromFile): Factor in file
modification time in hash key generation.

Abstracted record toolbar to a separate driver-linked template to allow toolbar customization on a driver-by-driver basis.