Change file permissions for some setuid executables so they are "o+r".
The executable itself doesn't contain any privileged information.

An example of where this is useful is when makefs(8) is creating an image
that includes /sbin/shutdown. This can now be done without root privileges.

Reviewed by:	delphij
Discussed with:	delphij, des
CR:		https://reviews.freebsd.org/D662
vt(4): Test if the cursor is shown only once

Later, we just see if the "struct mouse_cursor" pointer is set. This
avoids the need to mess with all the conditions several times; this has
been error prone.

While here, rename the variable "m" to a more meaningful "cursor", like
it's done elsewhere in the code.

MFC after:	1 week