new package: added package 'iftop'

Signed-off-by: Stephan Raue <stephan@openelec.tv>
iftop: fix build

Signed-off-by: Stephan Raue <stephan@openelec.tv>
libpcap: dont build shared library

Signed-off-by: Stephan Raue <stephan@openelec.tv>