Consolidate common code
Move most the code for generating/parsing JSON into a base class

This will allow me to write the disk usage tracker without
repeating myself.
Move the base tracker to its own file
Move memory-usage specific stuff into memory_tracker.py
Add a disk tracker

The disk tracker isn't currently displayed in the output.
Fixing bad copy-paste
Ignoring build and dist
Make it easier to plot more things
Also dump disk space
Show free disk space in plotfree
Shrink graphs vertically
Don't show points
Moving CSS/JS into assets folder
Don't show times in x-axes
Add Bootstrap 2.1.1
Switch to Bootstrap for styling