David Adam 2747945c55 [cmake] don't try too hard to create extra vendor directories
Homebrew and other systems set the path for the extra completion,
function and configuration directories outside the writeable prefix.

Mirror the autotools build in trying to create these directories, but
not causing the whole install to fail if this operation in unsuccessful.
2018-02-27 20:42:58 +08:00
..
2017-11-17 16:21:55 +08:00