Updated data files

Updated files in "Data" folder. There are two sample trials: 2_CS_1F_20
("Crowd Straight") and 4_SW_2_3 ("Swarm"), which are more or less
representative of a 'small' and 'large' file, respectively. Each
contains three versions: *.qtm (raw motion capture data in Qualisys
format), *.mat (raw motion capture data in MATLAB format), and F*.mat
(processed position data from importSwarmData).