Merge branch 'master' of github.com:openwebwork/webwork-open-problem-library
Merge branch 'master' of github.com:openwebwork/webwork-open-problem-library
Remove 'Law of Sines' from Keywords because it is not used.
Change DBsection and Keywords to 'Law of Cosines' for a side-angle-side task.
Revise confusing instructions,
then use minimal MathObjects stuff to handle NONE as a possible answer.
Merge pull request #50 from Dick-Lane/master

revise tagging for 5 problems and fix 1