Working on #42
- Added simple upstart script
- Added Keys
- Added Tasks
- Incremented sbt version to 0.13.0 for testing (maybe reverted in next
commits)

Moving upstart script to DebianPlugin and adding TaskKeys #42
Some cleanup of template generation and upstart support.

* Created a new java_server archetype for projects.
* Moved upstart configuration into java_server archetype
* Moved chmod method into common, hacky location.
Merge remote-tracking branch 'origin/master' into wip/jsuereth-upstart
Fix typo and ensure that upstart configuration works.

* Typo was causing upstart script to be ignored in favor of bash.
* For some reason chdir wasn't working on my local ubuntu.  Workaround issued.
Wire upstart debian maintainer script configuration through the plugin.

* Create new tasks which genreate prerem/postinst scripts
* Automatically use files generated by these tasks, if they exist.
* Java server archetype now automatically creates prerem/postinst scripts to
  start up the service upon install.
Adding correct maintainer and packageSummary. 
Changing 'chdir' to correct path. Ticket #42
Merge pull request #44 from muuki88/master

Working on #42