ORBIT, plus tests for LE, IN, and PM.

Started building ORBIT library.
Tinkering this together drove some changes into the testing library.
The "LE" tests apply operator<= and expect true.
The "IN" tests check inclusive ranges. May use either or both of <= and >=.
The "PM" tests check "within epsilon of expected" and may use add, subtract, >=, and/or <=.