Revert "Use install instead of cp."
Revert "Use install instead of cp."

This reverts commit 679f823108abe3e9710adb8f514120eb56f0a128.

install -D is different on BSD systems.

chrismoulton/Varnish-Cache,feld/Varnish-Cache,varnish/Varnish-Cache,franciscovg/Varnish-Cache,franciscovg/Varnish-Cache,mrhmouse/Varnish-Cache,gquintard/Varnish-Cache,ajasty-cavium/Varnish-Cache,varnish/Varnish-Cache,gquintard/Varnish-Cache,chrismoulton/Varnish-Cache,zhoualbeart/Varnish-Cache,varnish/Varnish-Cache,ajasty-cavium/Varnish-Cache,gauthier-delacroix/Varnish-Cache,chrismoulton/Varnish-Cache,mrhmouse/Varnish-Cache,gauthier-delacroix/Varnish-Cache,mrhmouse/Varnish-Cache,feld/Varnish-Cache,zhoualbeart/Varnish-Cache,gauthier-delacroix/Varnish-Cache,chrismoulton/Varnish-Cache,franciscovg/Varnish-Cache,gauthier-delacroix/Varnish-Cache,varnish/Varnish-Cache,ajasty-cavium/Varnish-Cache,feld/Varnish-Cache,zhoualbeart/Varnish-Cache,zhoualbeart/Varnish-Cache,chrismoulton/Varnish-Cache,feld/Varnish-Cache,gquintard/Varnish-Cache,franciscovg/Varnish-Cache,zhoualbeart/Varnish-Cache,varnish/Varnish-Cache,gquintard/Varnish-Cache,gauthier-delacroix/Varnish-Cache,franciscovg/Varnish-Cache,feld/Varnish-Cache,mrhmouse/Varnish-Cache,ajasty-cavium/Varnish-Cache,mrhmouse/Varnish-Cache,ajasty-cavium/Varnish-Cache