codestyle: Ensure modifiers are all in order
codestyle: Ensure modifiers are all in order

The Java Language specification, sections 8.1.1, 8.3.1, 8.4.3 and 9.4
recommend that modifiers be specified in this order:

1. public
2. protected
3. private
4. abstract
5. default
6. static
7. final
8. transient
9. volatile
10. synchronized
11. native
12. strictfp

Fix violations of the above ordering.

snehasp13/main,snehasp13/main,nightism/addressbook-level4,nightism/addressbook-level4,CS2103AUG2016-T11-C4/main,CS2103AUG2016-T11-C4/main