cmake: update revision to 3.7.3git
fft: fixed logpwrfft.py to import new C++ window properly from fft_swig (fixes issue #609 reported by Sylvain Munaut).
fft: put include protections around window.h (fixes issue #610 reported by Sylvain Munaut).
Update revision to 3.7.2

(moved 3.7.2 release to this commit)