BETA 0.2.1 - GUI improvements, job generation bias

Minor GUI improvements. Job location arrows now change color based on
the distance. Job destination now shows a green circle. Added company
info to the F5 help menu. Boosted all job rewards x4. Added a bias
towards shorter-distance jobs during job generation (the script will
generate multiple jobs and choose the shortest one that it finds). This
can be configured to change the number of iterations (default is 4, set
it to 1 if you want jobs to be completely random).