Add test for emitting modifier order in compliance with JLS.
Merge pull request #53 from square/jw/modifier-order-test

Add test for emitting modifier order in compliance with JLS.
Merge remote-tracking branch 'upstream/master'

Also fix ordering issue, which is why EnumSet.copyOf was being used
initially.

Conflicts:
	src/test/java/com/squareup/javawriter/JavaWriterTest.java