Log Message:
waf: update to 2.0.22.

NEW IN WAF 2.0.22
-----------------
* Fix stdin propagation with faulty vcvarsall scripts #2315
* Enable mixing Unix-style paths with destdir on Windows platforms #2337
* Fix shell escaping unit test parameters #2314
* Improve extras/clang_compilation_database and extras/swig compatibility #2336
* Propagate C++ flags to the Cuda compiler in extras/cuda #2311
* Fix detection of Qt 5.0.0 (preparation for Qt6) #2331
* Enable Haxe processing #2308
* Fix regression in MACOSX_DEPLOYMENT_TARGET caused by distutils #2330
* Fix extras/wafcache concurrent trimming issues #2312
* Fix extras/wafcache symlink handling #2327