script/scancpan: add -host & -target options

Signed-off-by: Francois Perrad <francois.perrad@gadz.org>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
perl: skip some tests which need the toolchain
perl: skip one test for DynaLoader
perl: check date in harness
perl: build with host-qemu
pkg-perl: with qemu
qemu: bump to version 1.7.0
perl: bump version to 5.19.7
perl: bump to version 5.19.8
perl: bump to version 5.19.9
perl: blead