pc-import: using psutils for platform independence
pc-import: using psutils for platform independence

replaced the "manual" looking for a terminal with psutils functions.
This should work at least on Linux, OS X and FreeBSD, with some luck on
all POSIX systems.

This fixes github issue #29

Savar/pycarddav,Savar/pycarddav,geier/pycarddav,geier/pycarddav