shorten/cleanup/fix TTY-pattern

removed BSD/Linux-specific TTYS, as there are several more TTY-names under even under linux than /dev/pts/${NONNEGINT}.
This also allows
 * "/dev/ttyUSB0"
 * "/dev/ttyS0"
Merge pull request #448 from Finkregh/patch-1

shorten/cleanup/fix TTY-pattern
Merge git://github.com/logstash/logstash