Read default attributes using OpenSSL config

Without this patch the Rake tasks prompt for attributes from rake
itself.  This leads to a number of issues:

 * Password needs to be provided for each private key
 * No default attributes for SSL certificates
 * Harder to issue SSL certificates with minor customizations

This patch addresses the problem by splitting the configuration file
into two files.  The first is for the Root CA itself which provides a
default Common Name suitable for the CA.

The second configuration file is for the SSL certificates.  The
attributes are largely the same as that of the CA but the default CN
field is read from the environment rather than from the configuration
file.

This could probably be consolidated.
Consolidate to one openssl.cnf

Without this patch we have two full configuration files and an ERB
template that needs to be filled in.  This is unnecessary because we've
switched to prompting the user with default values using OpenSSL rather
than Rake.

This patch removes the unnecessary behavior of populating the ERB
template and creating two configuration files, one for the CA and others
for the SSL certificates.

With this patch applied we have only a static OpenSSL configuration file
and the Rake task is largely about setting the CN environment variable.
Update README
Merge pull request #1 from jeffmccune/puppetlabs

Merge jeffmccune's changes