Ports that build out of source now simply can use "USES=cmake"
instead of "USES=cmake:outsource". Ports that fail to build
out of source now need to specify "USES=cmake:insource".
I tried to only set insource where explictely needed.
PR: 232038
Exp-run by: antoine
Simplify some ports where DragonFlyBSD no longer needs to be special-cased.
Submitted by: rene
Reviewed by: bapt, jbeich
Differential Revision: https://reviews.freebsd.org/D17724