Remove $Id: lines as leftovers from CVS

-- Remove all lines containing $Id: by executing
   perl -pi -e"s/^.*\\\$Id:.*\n//" `git grep -l "\$Id:"`

-- possible remove an "empty" line, surrounding the former $Id: lines

-- in ptclient/pt(expire,loader).c replace CVS version with git version.
ptclient/ptloader.c: fixup last commit #include xversion.h
configure: make mmap test error-free
cache_parserecord: make static
mailbox: don't magically rebuild the cache

This is one of many misguided "magic repair" things that I put
into Cyrus 2.4.  I've never heard of it improving matters, but
it adds unpredictable behaviour.  Generally if the cache has
failed to exist, it's because something is broken that means
building a new cache won't work either.

Throw an IO error and make the sysadmin fix things, and chances
are you won't need to rebuild the cache anyway.
mappedfile: don't assert locks, we can be used unlocked
mappedfile: export API

It's going to be used for cache files in mailbox.c, and probably many
others as well soon
mappedfile: add pwritebuf API
mappedfile: support readonly filehandle

When you only want to read from a file, it's more polite to
open it read-only, not only for the OS to optimise, but
it's a safety thing for your own code!

This patch adds a new flag to mappedfile_open
mappedfile: use struct buf internally

This is part of a general "make our components re-usable
and actually re-use them" drive!
crc32: take a const struct buf