support/script/scancpan: add option test

test modules are usually useless on BR
perl: bump to version 5.20.0
perl: skip some tests which need the toolchain
perl: fix test IO-Socket-IP
perl: check date in harness
perl-cross: testpack
qemu: add a Config.in.host

after the removal of cpanminus
perl: remove useless modules in target tree

with BR, we never install module from the target
perl-config-tiny: new package
perl-curses: new package
perl-io-socket-ip: new package