base/deploy: support for default Procfile in platforms

Related to #39, tsuru/tsuru#545 and tsuru/tsuru#875.
java: support war deployment

Users can now upload war files. We're using tomcat with a hard coded xmx
value, I plan to make it customizable, but not now :)

Closes #39.
java: allow customization of xmx value

We may customize other stuff in the future.