Correct a couple of brain-o's in the allocation logic:
Correct a couple of brain-o's in the allocation logic:

Reserve space for the objects entry in the index, when the object
is allocated.

Allow smaller than requested allocations for non-object allocations.

Attempt allocation from three segments, then give up.



git-svn-id: 7d4b18ab7d176792635d6a7a77dd8cbbea8e8daa@4270 d4fa192b-c00b-0410-8231-f00ffab90ce4

CartoDB/Varnish-Cache,ssm/pkg-varnish,CartoDB/Varnish-Cache,ssm/pkg-varnish,wikimedia/operations-debs-varnish,wikimedia/operations-debs-varnish,wikimedia/operations-debs-varnish,CartoDB/Varnish-Cache,wikimedia/operations-debs-varnish,ssm/pkg-varnish,ssm/pkg-varnish,wikimedia/operations-debs-varnish,ssm/pkg-varnish