[FAB-3259] Make cryptogen output more flexible

This patch enhances the cryptogen tool by providing a more
flexible configuration and output operation, based on a
YAML config file and golang templates.

Summary of changes:
-------------------------

*) Tool now has two subcommands
   *) "generate" - This takes the role of the previous top-level
                   command.  It gets rid of almost all of the
                   previous command-line switches and replaces them
                   with:

       -output: specify the output directory.  defaults to
                crypto-config
       -config: specify the input configuration file.  defaults to
                a configuration similar to before (1 orderer, 2 peer
                orgs, 1 peer/org

   *) "showtemplate" - Prints the built-in default template to
                       standard out, suitble for saving/editing
                       for future "generate" sessions.

*) CommonName outputs are now much more DNS friendly.  For example: we
   now use "peer3.org1.com" in favor of "peerOrg1Peer3".  Users also gain
   total control over the generation of the CommonNames with various
   templating facilities. See "cryptogen showtemplate" for more details.

Change-Id: I5968a794d4469ada8d3b90e112bdfe93e77c9661
Signed-off-by: Gregory Haskins <gregory.haskins@gmail.com>