MATH-1118
Fixed compatibility of "equals(Object)" with "hashCode()" ("Complex" will
behave as JDK's "Double"). Added new methods for testing floating-point
equality.
Thanks to Cyrille Artho for reporting the issue.


git-svn-id: https://svn.apache.org/repos/asf/commons/proper/math/trunk@1588500 13f79535-47bb-0310-9956-ffa450edef68