This is a major change of how the filters are interpreted. If everything
works how it should, it should not affect you unless you are hacking the
filters themselves.
Anyway, this change should make a huge improvement in the filter performance
as previous benchmarks showed that our major problem lies in the
recursion itself.
There are also some changes in nest and protocols, related mostly to
spreading const declarations throughout the whole BIRD and also to
refactored dynamic attribute definitions. The need of these came up
during the whole work and it is too difficult to split out these
not-so-related changes.
We set buffer->pos to buffer->end in function buffer_print() when
bvsnprintf() failed, so there would be uninitialized memory between
the old buffer->pos and the current buffer->pos.
Prefix sets were broken beyond any repair and have to be reimplemented.
They are reimplemented using a trie with bitmasks in nodes.
There is also change in the interpretation of minus prefix pattern,
but the old interpretation was already inconsistent with
the documentation and broken.
There is also some bugfixes in filter code related to set variables.
