Adding support in CPU monitoring

Adding two new collectors and a controller to enable
monitoring the CPU tuning parameters: vcpu_quota, vcpu_period.

This patch is part of the CPU SLA feature: http://www.ovirt.org/Features/CPU_SLA.

Changes in collectors:
Added a new utility method to Collector.py, "count_int",
count the number of matches in a string according to a regular expression.

Added HostCpu to expose the number of cpu on the host.

Added GuestCpuTune to expose the current tuning parameters and the latest user selection

Changes in controller:
Added CpuTune to apply changes to the vcpu tuning.

This patch is used in the cputune.policy, some code snip:
(defvar anchor 100000)
(def check_and_set_quota (guest)
{

    (defvar calcQuota (/ (* anchor (/ guest.user_vcpu_limit 100))) guest.vcpu_count)

    (if (!= guest.vcpu_quota calcQuota)
        (guest.Control "vcpu_quota" calcQuota) 0)
})

Change-Id: I31428499ae7b34cafa3eacf5ca0d7a39eabe23ec
Signed-off-by: Kobi Ianko <kianku@redhat.com>
Reviewed-on: http://gerrit.ovirt.org/27240
Tested-by: Kobi Ianko <kobi@redhat.com>
Reviewed-by: Adam Litke <alitke@redhat.com>