Updated filters specification

As promised (but late! sorry) here is an updated Filters specification. We've moved to Mercurial, so forgive the complex URL:

https://dvcs.w3.org/hg/FXTF/raw-file/07eb4eb9f3ed/filters/publish/Filters.html

Or for the latest version, whatever that may be at the time you click:

https://dvcs.w3.org/hg/FXTF/raw-file/tip/filters/publish/Filters.html

I've included a ChangeLog, but in general the changes are:

- renamed the main file (removing "svg")

- temporarily comment out reqs and primer publications
  (I'm not sure these are needed any more)

- update the intro section to be more language neutral

- define the filter property in terms of a list of functions
  which is a space separated list of commands like url(), sepia() etc

- define the most useful shorthand functions and show the equivalent
  <filter> version for each shorthand function. I only picked the functions
  that have an equivalent at the moment. Future versions may include
  more shorthands, which may mean more <fe*> operators.
  Note: definitions of "useful" may differ. I don't consider the
  lighting functions terribly useful, but they can be easily added if
  requested.

I've also put a big warning in the CVS version pointing at this new spec.

I realise there isn't a call today, so please bombard the list with comments and complaints.

Dean