Fix a problem when the variables were set to value exactly at the lower/upper boundary. We do to set the initial value to half of the range, but just to a value close to the boundary.
Use modified formula for tq-tilde only when qmu is significant larger than qmu_asimov. Avoid in particular the case when both are very close to zero.
use -ffast-math instead of —fast-math which is not valid anymore in the latest clang version (5.1)