Revert "removed sigplanconf-guide.pdf"

This reverts commit fde1db2e063d26fef82939f1d2678f929703ade4.
soundness proof

the last qed example is missing
fixed untracked files
split reduction-for-tso

started modularizing the .tex source files; section reduction for tso
is put into a new file, reduction-for-tso.tex