Switched to a slightly faster (and more accurate) approximation for erfc()
Reversed a change that didn't help
Merge pull request #615 from peastman/master

Switched to a slightly faster (and more accurate) approximation for erfc()
Updated code to obey BUILD_TESTING to allow for disabling of test compilation
Merge pull request #617 from Omegaice/master

Updated code to obey BUILD_TESTING to allow for disabling of test compilation