Log Message:
Updated waf to 1.9.3.

NEW IN WAF 1.9.3
----------------
* Improve the behaviour of parallel configuration tests (conf.multicheck) #1793
* Fix the Fortran Nag compiler detection #1797
* Detect Qt 5.7 (-std=c++11 flag) #1800
* Detect Boost python on Gentoo #1802
* Update the strip and netcache examples