client: Source format

Using the GWT style.
Add Alastair's suggested changes to DSATest from code review

https://codereview.appspot.com/7308090/diff/1/common/src/test/java/com/google/nigori/common/DSATest.java
Signed-off-by: Daniel Thomas <drt24@cam.ac.uk>
appengine: Source format using GWT
test: Source format with GWT