Made all the tasks successfully the average task length for each stage!

But the tasks still start as if they were not at their average lengths, causing weird spaces in waterfall. Fix this.

Learned some python today.. learning where things are instantiated and everything like that.
created a make_avg function, which is used in stage's alter_events_to_average_runtime function to change all the runtimes to average runtimes once it is called.
Made a new definition alter_events_to_average_runtimes definition, which calls task's function make_avg to make all the runtimes the average runtime.