* getkey.c (merge_selfsigs_main): Don't bother to check designated revoker
sigs if the key is already revoked.
* packet.h, getkey.c (merge_selfsigs_main): New "maybe_revoked" flag on
PKs. It is set when there is a revocation signature from a valid
revocation key, but the revocation key is not present to verify the
signature.
* pkclist.c (check_signatures_trust): Use it here to give a warning when
showing key trust.
* compress-bz2.c: Include stdio.h. Solaris 9 has a very old bzip2 library
and we can at least guarantee that it won't fail because of the lack of
stdio.h.
* g10.c (main): Add read-only warning.
* compress.c (compress_filter): Make static to help force the use of
push_compress_filter. Remove default algorithm setting since that is done
in push_compress_filter now.
* main.h: Use named algorithm.
* filter.h, compress.c (push_compress_filter, push_compress_filter2): New.
Figure out which is the appropriate compression filter to use, and push it
into place.
* compress.c (handle_compressed), encode.c (encode_simple, encode_crypt),
sign.c (sign_file, sign_symencrypt_file), import.c (read_block), export.c
(do_export): Use push_compress_filter instead of pushing the compression
filter ourselves.
* compress-bz2.c: New. Bzlib versions of the compression filter routines.
* Makefile.am: Include compress-bz2.c if bz2lib is available.
