One likely fix, 2 cosmetic fixes, udev-rules-file

[avl42]

This PR adds the following:

"etc--udev--rules.d--24-TEMPer.rules"
This file can be copied to /etc/udev/rules.d/24-TEMPer.rules, then any of the
supported thermometers will have their device-entries (hidraw* or tty*)
be read- and writeable by all users of group "plugdev" - allowing to use
temper.py without sudo.

In temper.py there is one change in a regular expression.
A couple lines down from that there was a "recent" change in
a similar regular expression, and it makes sense for me, that
the two regular expressions should be structurally equal.
But then again, I do not own one of these devices, so I cannot
test them myself.
The removed semicolons ";" are purely cosmetic, and so is
the one change in a function's comment.

Take it, leave it, or cherrypick it... :-)