Add debug mode to burnin
Add debug mode to burnin

There are two entry points to job execution in burnin, ExecOp and
ExecOrQueue, and these are modified to call the new _SetDebug method on
the opcodes.

Signed-off-by: Iustin Pop <acf83a5274f31a43af6b914614365999469c1a31@google.com>
Reviewed-by: Michael Hanselmann <68b67885ff74281219b4a4be33cc20fd45078d7c@google.com>

ganeti/ganeti,apyrgio/snf-ganeti,bitemyapp/ganeti,ganeti/ganeti,leshchevds/ganeti,leshchevds/ganeti,ganeti/ganeti,bitemyapp/ganeti,ganeti-github-testing/ganeti-test-1,leshchevds/ganeti,onponomarev/ganeti,apyrgio/ganeti,mbakke/ganeti,apyrgio/ganeti,andir/ganeti,grnet/snf-ganeti,yiannist/ganeti,mbakke/ganeti,dimara/ganeti,andir/ganeti,apyrgio/snf-ganeti,andir/ganeti,ganeti-github-testing/ganeti-test-1,grnet/snf-ganeti,mbakke/ganeti,onponomarev/ganeti,yiannist/ganeti,yiannist/ganeti,dimara/ganeti