Update minecraft module for Puppet 2.7 and Minecraft 1.7.2

When I tried to install minecraft with this module, I found that version 1.5.2 was being downloaded, and the minecraft server was not starting up cleanly.  I made the following changes to make things work more smoothly:

 * Enabled service minecraft and installed sysv-rc-conf or chkconfig to insure that the minecraft would start. 
 * Added a 'version' parameter to minecraft class. 
 * Initialized server.properties from a template file, so that the server_prop class will work. 
 * Update name of s3file to s3::file.

Please see also required PR on the s3 module:

https://github.com/branan/puppet-module-s3file/pull/5