More sample sound effects

From reading the script, I noted the extra sound effects that we need.

Here are some samples:

Marching

http://freesound.org/people/WebbFilmsUK/sounds/200321/

http://freesound.org/people/stib/sounds/240732/

Crowd shouting

http://freesound.org/people/benjaminharveydesign/sounds/316640/