Fon

Fon is used at run time in 4 crates (of which 1 optionally).

Number of dependers	Fon version	Downloads/month
1	0.6.0	51K
2	0.5.0	28
1	0.4.0	15

Depender (with downloads and own rev deps)			Fon version
	2	wavy		^0.5
	1	twang		^0.6
		raw_audio		^0.5
		cala	optional	^0.4