Added a dummy target to allow the desktop to tweet me with the build results
Debugged 'make tweet' to get it all working
Changed definition of asymptotic variance

I changed the asymptotic variance to use an asymptotically equivalent
formula that I think will do better in finite samples.  I also made
a few very minor edits to the paper text.
Minor change to 'thanks' section
Fixed typo in math
Removed make-to-tweet
Added heteroskedasticity to mc2
Commit