Improve PLL lock testing
Improve PLL lock testing

In internal try and catch the intermittent lock when an external
reference is applied.  In limited testing seems to catch at least 9 out
10 times.

--CAR

Plourde-Research-Lab/Qlab,BBN-Q/Qlab,Plourde-Research-Lab/Qlab,BBN-Q/Qlab,Plourde-Research-Lab/Qlab,BBN-Q/Qlab,BBN-Q/Qlab