system: Add acl-aware perl wrapper.

By default, permission checks in perl only use the normal mode bits,
instead of the access(2) function. Adding "use filetest 'access';" to
the program, or the equivalent "-mfiletest=access" to the commandline,
we get proper behaviour when ACLs are involved.

diff --git a/usr/local/bin/aclperl b/usr/local/bin/aclperl
new file mode 100755 (executable)
index 0000000..75911b7
--- /dev/null
+++ b/usr/local/bin/aclperl
@@ -0,0 +1,2 @@
+#!/bin/sh
+exec perl -mfiletest=access $@