Allow users to track custom NPCs by ID.

This should be trackable in the GUI, and new entries should be added in the GUI.

I think NPCScan has done something similar already, so look at that.

Example of data needed from user, where (...) indicates optional:

[id,
display_name,
(exact-time: time) OR (rand-time: min-max),
(zone),
(color),]

If this is something that would take too much time/effort to code in (considering the ticket is just over 4 years old, would you be willing to provide a template file we can input our data into and drop into our addon folders manually, for slightly more advanced users? There are SO many rares that can be tracked now, and I would much rather use WBT than an unnecessarily showy WeakAura or similar. Thanks!

There are a bunch of issues which made me not implement it yet:

1. I don't want to spend much time.
2. I don't want to worry about preserving important data (i.e. if users build large collections of custom rares etc.)
3. It's unknown how to handle sharing of such timers (maybe just disable it)
4. It won't be of much value without adding a GUI for browsing and editing custom timers. Lots of work.
5. More.

So overall it's more work than I'm willing to do right now.

The proposal of having a template to fill in would be more in line with what I'd be OK with supporting. That would pretty much be that WBT loads and merges another table with what already exists in BossData.lua today. It requires editing lua files though.

@fstenstrom There are many NPCs that would be great to add to track spawn time. For example Timeless Isle rares or any other world rares with low chance of item drop and some known time to be spawn