Update a 'missing' build script from der_tiger

Build of 2.9p5 issues a warning:

./owfs-2.9p5/src/scripts/install/missing: Unknown `--is-lightweight'
option
Try `./owfs-2.9p5/src/scripts/install/missing --help' for more
information
configure: WARNING: 'missing' script is too old or missing
Current autoconf versions will create code to check, if the 'missing'
script is up-to-date. In order to get rid of this error, please, update
the missing script to the most recent version, like the one privided by:
http://git.savannah.gnu.org/cgit/automake.git/tree/lib/missing
CVS ID removals
potential string without null termination

Coverity
one error message path didn't reset arguments

Coverity bug
Unneeded check after getline

Coverity bug
Merge remote-tracking branch 'origin/master' into darwin