Merge pull request #21 from piti118/better_integral_binlh

add nint_subdiv to control how binned chi^2 and binned LH calculate expected number of event
Merge pull request #22 from piti118/better_integral_binlh

clean up doc
Add option show_errbars to draw_ulh so one can show error bars in data. Add *~ to .gitingore.
merge with upstream
Add back the files that aren't supposed to be untracked.
Use Simpson's rule in  integrate1d_with_edges.
Undo the Simpson's rule. Add new baseline images after modifying draw_ulh.
Merge pull request #23 from gitcheng/master

Errorbar option in draw_ulh; Simpson's rule in integrate1d_with_edges
simpson3/8 and change default integral interval/faster test
update c file