Xen 4.4 CentOS v2

Signed-off-by: David Scott <dave.scott@citrix.com>
Incorporate jonludlam's cleanups

Signed-off-by: David Scott <dave.scott@citrix.com>
Merge pull request #524 from djs55/centos-4.4

Xen 4.4 CentOS v2
Use xen-4.4.9 debs based on Thomas Leonard's ARM branch

Signed-off-by: Jon Ludlam <jonathan.ludlam@citrix.com>
xen-utils isn't a development package

Signed-off-by: Jon Ludlam <jonathan.ludlam@citrix.com>
Don't try to build mirage stuff on ARM

Signed-off-by: Jon Ludlam <jonathan.ludlam@citrix.com>
Fix parallel make

Flock does not have queueing, so it's very possible that multiple threads
will cause a timeout of one of the threads.
Further, the createrepos only needs to be run once to pull in all SRPMs or
all RPMs.

This change creates a queue which will run createrepos a minimum number of
times, blocking make until createrepos has been run for that particular
(S)RPM.
Merge pull request #526 from BobBall/parallel-fix

Fix parallel make
Merge pull request #525 from jonludlam/arm-xen-4.5

Arm xen 4.5
Fix potential 'race' where the first timeout would be hit

Process A writes to the queue
Process B executes + clears the queue
Process C writes to the queue
Process A will now never be head and will just sit until the queue
is empty again or the timeout is hit.

Also fix definite race where the queue could get broken because part
of the code was expecting PIDs
Merge pull request #527 from BobBall/parallel-fix

Fix potential 'race' where the first timeout would be hit