Merge pull request #1 from mgage/master

PGalias.pm is now in reasonable shape
Merge pull request #12 from goehle/master

Fixed uninitialized score variable
Fix problem with detecting NAN when it is capitalized or negated
Fixed typo in comments
New OneOf MathObject for creating answers that can be one of several correct values.
Merge pull request #13 from dpvc/parserOneOf

Adds OneOf MathObject class for answers that can be one of several correct answers
Added a macro to calculate the mean of an array of data, and another
macro to calculate the standard deviation of an array of data.
Add support for new compoundProblem method
Merge branch 'openwebwork-dev'
When $main::PG->{QUIZ_PREFIX} not defined, definition of $answerPrefix was polluting the error log
Empty string for $bHTML and $eHTML a lot of "unitialized value in concatentation" messages in error log. Changed default values to " " instead of ""
Merge pull request #14 from discnerd/master

Descriptive Stats macros
Merge pull request #15 from aubreyja/master

Cleaned up code in parserMultiAnswer.pl and unionTables.pl that was causing a lot of spurious and unattributed messages to be written to the error log.
Fix typo in comment.
Add parserFunctionPrime.pl macro file that implements prime notation for parserFunction objects.
Merge pull request #16 from dpvc/master

Add parserFunctionPrime.pl macro file
Remove 'defined' from deprecated defined(@array) in MathObjects (resolves issue #17).
Merge pull request #18 from dpvc/master

Fix problem with defined(@array) in MathObjects
Use getVariableLimits to get limits for diagnostic graphs (so that they are handle the same way as the answer checking itself)
Merge pull request #19 from dpvc/master

Fix diagnostic graphs to use correct limits when specified in context