CRM-13434 Send more through hook_civicrm_links

There are tons of places action links in CiviCRM, but practically none can be altered through hook_civicrm_links.  This change does several things:
* It provides the relevant information (operation, object name, and object ID) to hook_civicrm_links to meet the promise of what that hook is trying to do for all the action links I could find.
* It passes the fill-in values for the URLs to the hook (requiring changes to the hook structure to allow a 6th argument).  Otherwise, it's hard to get enough context in many places or to edit the links in a meaningful way.
* It indexes the links sequentially instead of by binary values that are filtered by bitmask.  The old method was making it next to impossible to be sure an added link won't be filtered out or overwrite another link.  This has the side benefit of allowing you to add additional links that show or hide based on the bitmask.