Add enable_if_lvalue to beast library
Wrap RippleCalc into a single function.
[fold into 684d4de] Cleanup RippleCalc based on feedback.
* Change public members of Input and Output to remove trailing _.
* Remove Input constructor and separate flags in RippleCalc to reduce
* duplication and confusion.
* Make calculation result private; add getter.
* Narrow scope of some of the results of calls to rippleCalculate.