Integrate numeric functions contributed by Bibudh Lahiri -- Thanks, Bibudh! --
and patch HSQL backend and VoltDB type system issues found in unit testing them.
Merge branch 'master' into ENG-4008

Conflicts:
	tests/frontend/org/voltdb/regressionsuites/TestFunctionsSuite.java
Throw an SQL-compliant error for numeric functions that result in NaN or Infinities.
Make numeric processing in the HSQL backend more SQL compliant, mostly with changes cherry-picked from a later version.
Add a functions unit test to run HSQLBackend interference for past sqlcoverage issues
Rewrote sqlcoverage IdGenerator to avoid id duplication, so sqlcoverage tests get more rows, fewer uniqueness constraint violations.
Integrated review feedback. r=aweisberg
Merge branch 'master' into ENG-4008
Switch over to more portable, more robust floating point error handling in both functions and operators.
Merge branch 'master' into ENG-4008
Merge pull request #310 from VoltDB/ENG-4008

Eng 4008