Make megaplot nicer

A bunch of megaplot updates.

• Aesthetic updates for pages run with --fullOnly
• Bayes factors for --fullOnly runs (ratio of iterations spent in full vs signal/glitch only)
• Fix model dimension histograms so bin is centered around integer
• Made megaplot compatible with an arbitrary number of detectors (used to be hard coded to three)
• fixed some deprecation warnings
• Got rid of a lot of useless code

Examples:

fullOnly

4 IFO