Is your feature request related to a problem? Please describe.
There are quests that come out that I would like to keep track of across all my toons, for instance, in the latest patch (10.1), there is "A Worthy Ally" and "Fighting is Its Own Reward"

Describe the solution you'd like
Through the UI, I would like to be able to manually enter a quest into the "monitor" list. It could be as sophisticated as adding a button the quest log, or as simple as providing input fields in the options area to allow one to enter the pertinent information.

Describe alternatives you've considered
Currently editing "Progress.lua" to have them show up. PITA because after every update the file needs to be updated again.

Additional context
This could be extended to add "inventory" currencies, such as the crests for example.

Where can I support the request? ;-)

I do like the idea of adding custom quest IDs.

The tracking of inventory items is out of scope though. Inventory scanning is a lot harder than keeping a database of the currency tab. There are quite a few trackers for this already: TSM, Altoholic, etc.