PKT_SCHED: tcf_exts API & make classifier changes consistent upon failure

Dave,

The following patchset adds tcf_exts API to remove the ifdef clutter, helps make changes consistent upon failures, makes adding action bits to yet unsupported classifiers as easy as adding a few lines and generally saves a lot of code per classifier. The patches to make use of the API add action support to all classifiers and makes changes consistent except for indev failures (to be removed soon) and rsvp which needs a closer look since i haven't had time to perfectly understand it yet.

I gave it extensive testing for 2 weeks, patches 5-6 are non-trivial though and it's quite hard to test everything. I will post a request to the lartc mailinglist once these changes are in a bk release so everyone can try it out and I have time fix any remaining issues before the next rc release. I could provide the patchset but its quite some work for the testers and I guess there will be more people trying it out if they can use an official release.

Cheers, Thomas