We used to link both libraries at once, but now that I'm working on
TLS, there's nothing left to keep OpenSSL around for when NSS is
enabled.

Note that this patch causes a couple of places that still assumed
OpenSSL to be disabled when NSS is enabled
   - tor-gencert
   - pbkdf2

Also, add a stubbed-out nss version of the modules.  The tests won't
pass with NSS yet since the NSS modules don't do anything.

This is a good patch to read with --color-moved.

These functions exist only to expose RSA keys to other places in Tor
that use OpenSSL; let's be specific about their purpose.

We only ever need this to get us a DH ephemeral key object,
so make a function that does just that.

When it is set, include the NSS headers and libraries as
appropriate.  Doesn't actually use them yet, though.

Fun fact: these files used to be called log.[ch] until we ran into
conflicts with systems having a log.h file.  But now that we always
include "lib/log/log.h", we should be fine.

These were necessary long ago to work around a bug in VC6.

Split the network-only and compression-only parts of buffers into
the appropriate modules.

This change makes a whole bunch of things in torlog.c break, since
apparently I did not find all the fd dependencies.

Includes configuration files to enforce these rules on lib and
common.  Of course, "common" *is* a modularity violation right now,
so these rules aren't as strict as I would like them to be.

You have no idea how glad I am that this is automated.

I am calling the crypto library "crypt_ops", since I want
higher-level crypto things to be separated from lower-level ones.
This library will hold only the low-level ones, once we have it
refactored.