infra/perl: switch to using a reliable mirror

The mirror we currently use is not a mirror, it's the main archive.

It has a few shortcomings:
  - it might not contain all the versions of the modules we use,
  - it can be unavailable at times (like now, for example)

Switch to using a realmirror, that:
  - does a round-robin on the actual mirror, so availability is better
  - contains all versions of all modules (yes, mojolicious is there!)

As a consequence, switch mojolicious to use our standard mirror,

Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Cc: François Perrad <francois.perrad@gadz.org>
Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
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-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-curses: new package
perl-io-socket-ip: new package