[CRIU] Automatically detect dirty memory tracking

[Adrian Reber]

The main change of this patch series is to automatically detect
if memory tracking (and thus pre-dumps) are possible. If not
p.haul no longer tries to pre-dump the processes which leads to
a failure/abort on systems without memory tracking.

This change, however, makes p.haul incompatible with older criu
RPC versions as it requires the latest RPC definition. I could
add an additional try/catch around the dirty-tracking detection
to work around.

In addition this series adds the possibility to migrate shell-jobs.

		Adrian