added draft of second paper
Merge pull request #7 from benmontet/master

added draft of second paper
hogg needs make
ignore barf
title change
title change
section* -> title
Added cls file needed for compiling tex files
reference PDC and give basic astrophysical justification
etal shortcut
description of the model in braod terms
terminology discussion
formally posing the problem
Merge branch 'causal' of https://github.com/dfm/SaveKepler into causal

Conflicts:
	whitepaper/sk.tex