tweaks
Merge branch 'master' of https://github.com/piantado/LOTlib

Conflicts:
	LOTlib/Inference/MetropolisHastings.py
fixed merge
lots of reorganization; see MAJOR CHANGES
Merge branch 'master' of https://github.com/piantado/LOTlib
added MCMC Summary
Merged SampleCollector & MCMCSummary classes; added method to set top hypotheses in summary.
Re-organized SimpleDemo by putting some functions into methods in Utilities or Vector/MCMCSummary.
Added SimpleDemo2 - more complex than SimpleDemo, with infinite hypothesis space (generate by enumerate_at_depth).