Analysis template - working copy - warning and reset to last saved

Sarah raises an issue about current behavior:

* I make a template and provide my group with R/W access (V1)
* I or someone else modify (e.g. change a pop freq filter) that template but don't press save bca I forget, or I don't actually want to keep those changes (not versioned)

These changes are forgotten.
* I come back in 2 months (or 2 hrs) time and modify the template based on my experience with V1, thinking I'm modifying V1, but I'm actually modifying the un-versioned changes.
* I save (V2) and run my analyses, but am not aware that the interim changes have been applied and don't do a comparison between V1 & V2 bca I think I know what I've done.

This equally applies if I'm mucking around with the current version of the template, and accidentally change too much. There's no way to then re-load the previous version.

Suggestions:

* Unsaved changes are discarded when you leave the page or at least there's a warning as you leave.
* The link to the active version of the view saved templates takes you to an unlocked template (at the moment it takes you to a locked version).
* There's a warning that you're viewed a modified draft, not an actual template version.