* Re-write makedep.py for better performance and better parsing front-end
* Make srcclean deal with kinds of preprocessor abuse I never want to see in real life
(nw) The new parser front-end is better at recognising C++ syntax and
also substantially faster - bootstrapping a single-driver build should
be noticeably quicker. Having a single parser for C++, .lst and .flt
files also gets us a bit closer to making it simpler to create custom
subtargets.
* subhuntr.cpp: S2636 PVI was seemingly uncommented by mistake in 93308b483e - offsets and sound routing seem to be copy/pasted from somewhere
* phi: prettier config
* scramble.cpp, wallc.cpp: avoid some calls to subdevice<...>(...)
* makedep.py: open source files as UTF-8 (GitHub #5482)
* minimaws: be less trusting
* Fixed building using system utf8proc
* Fixed building using system portaudio
* Allow using system-wide asio headers (1.11.0 or higher required).
* Allow using system-wide glm headers
* Allow using system-wide rapidjson headers
* Put all ext_includedir calls together
* Fixed build failure when SOURCES is defined
