Adds support for a custom war file name

Currently the war name is always equals to ${project.build.directory}/${project.build.finalName}.war. This is overridable through the pom file in a project, but sometimes this behaviour is undesirable. That's whythis pull request adds support for a custom war name through the command line.

This pull request is divided into two seperate commits, one for tomcat6 and the other for tomcat7.