Merge pull request #85 from paulvojta/master

Bug fixes, mostly adding "+C" and adding helpLinks for interval notation
Only allow powers of 0 or 1 in answers
Fix a randomization bug
Merge branch 'master' of github.com:openwebwork/webwork-open-problem-library
Redo randomization to avoid 0 as a coefficient
Set part c absolute tolerance to 0.01
Set absolute tolerance to 0.01 in part c
updates to PCC Contribs BasicMath and Basic Algebra
Merge pull request #86 from Alex-Jordan/pccProduction

updates to PCC Contribs BasicMath and Basic Algebra
Fix bug 3152 (fix by J. Holt)
Fix bug 3159
Fix bug 3160.
Really fixing bug 3159 this time.
Fix bug 3162 (answers unscrambled twice).
Fix bug 3166 and clean up solution code.
Fix bug 3167, poor wording.
Change Compute("NONE") to List("NONE")

to provide consistent error messages.