In #36 some of the odd errors were due to seeks beyond the end of the
disc. This was because the disc was "specially crafted" to be 25GB + 1
byte, which doesn't fit into the normal 512 byte sectors expected of a
disc. This lead to reads going beyond the end of the disc etc.
If a similarly evil disc is used with `losetup`, it just ignores the
last bytes of the disc that don't fit into 512 chunks. This is what
that patch does, logging an error at the same time.
This commit beefs up the Makefile to do the build, instead of the
Rakefile.
It also removes from the Rakefile the dependency on rake_utils, which
should mean it's ok to build in a schroot.
The files are reorganised to make the Makefile rules more tractable,
although the reorganisation reveals a problem with our current code
organisation.
The problem is that the proxy-specific code transitively depends on the
server code via flexnbd.h, which has a circular dependency on the server
and client structs. This should be broken in a future commit by
separating the flexnbd struct into a shared config struct and
server-specific parts, so that the server code can be moved into
src/server to more accurately show the functional dependencies.
