wix: move contrib/wix to contrib/packaging/wix
We're trying to consolidate all our packaging code into
contrib/packaging. Let's move the WiX files there.
Differential Revision: https://phab.mercurial-scm.org/D6096
#require execbit
$ hg init repo
$ cd repo
$ echo foo > foo
$ chmod 644 foo
$ hg ci -qAm '644'
$ chmod 755 foo
$ hg ci -qAm '755'
reverting to rev 0
$ hg revert -a -r 0
reverting foo
$ hg st
M foo
$ hg diff --git
diff --git a/foo b/foo
old mode 100755
new mode 100644
$ cd ..