[Templates] TT and dependencies

[Perrin Harkins]

Keith G. Murphy wrote:
> I'm thinking more about situations where you've got multiple files that 
> are possibly prerequisites of the target file, and that can be via 
> INCLUDE, PROCESS, etc., or plugins.

I think the INLCUDE/PROCESS stuff is covered by the recent work, 
although I haven't been watching it closely.  Plugins (and arbritray 
PERL blocks, etc.) are not possible to detect a last-modified time on 
automatically, since they could depend on literally anything.  One way 
to cheat here is to manually declare a "touch file" which a template 
depends on.  Then you make your process which updates the database or 
whatever you're accessing with a plugin touch this file when it changes.

> Ahhh!!!  Perhaps the TAG_STYLE thing you did could at least be used to 
> specify dependencies

Yes, or maybe META.

- Perrin