Improved speed of several FastMath methods.

Double.doubleToLongBits replaced with Double.doubleToRawLongBits at
several places.

JIRA: MATH-953

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/math/trunk@1460587 13f79535-47bb-0310-9956-ffa450edef68