Revert "added dinvgamma source and updated dinvgamma in code"

This reverts commit 1b7963c9f04f08a64591c77ab4a162deff7c0f0f.
Revert "cleaned up code errors from git"

This reverts commit 92066b8676a004b5a964fef41c019c741851aed3.
Revert "Revert "cleaned up code errors from git""

This reverts commit db249e95755feb98d696574345b8461ace916421.