Add ctypes wrapper for openssl

Add a *ctypes* wrapper for the openssl (libcrypto) library.  The initial use for this is to add support for certificate verification that is not supported by m2crypto.  This further reduces our dependency on our own patched version of m2.

Later on, I think we should consider expanding the functionality and potentially eliminating our dependency on m2 all together and just use openssl. 

I also added server/common and added the module there.  I know this creates a package with one module but I'm pretty sure there are a number of other modules that really belong here.  We can move them later.