small intro tweaks
github link.
misc
Implementation
Merge branch 'master' of g.csail.mit.edu:nail

Conflicts:
	paper/intro.tex
Conclusion, eval, future work
minor nits in the intro
some relwk nits; one XXX regarding hammer vs nail
pass over design up to 3.2
done with pass over section 3 (design), another XXX note
conclusion
some small impl nits
future work pass
make spell
figure 4 spacing
spurious space
improve figure placement
fixed pdf
Merge branch 'master' of g.csail.mit.edu:nail

Conflicts:
	paper/concl.tex
	paper/eval.tex
	paper/future.tex
	paper/impl.tex
	paper/main.tex
try to merge the conclusions
Fixed XXX