Add POM generation/uploading to deploy:deploy-file goal

Attached is a patch to the maven-deploy-plugin to add the ability to upload either a specified or an auto-generated POM file as part of the deploy:deploy-file goal.

This adds two new options to the goal, and makes some options no longer required. Specifically, it adds:

• uploadPom - boolean, indicating whether pom should be uploaded
• pomFile - file, specifies the pom to use
  And it makes optional:
• groupId
• artifactId
• version
• packaging