[poolallocator,release] Removed leftover debugging output.

(cherry picked from commit c504cb3b3e33210fee9b592d9297e8d14ffd76a4)
Signed-off-by: Markus Blatt <markus@dr-blatt.de>

Manually resolved conflicts (due to change dune_static_assert -> static_asser
in master):
	dune/common/poolallocator.hh
[poolallocator] Throw bad_alloc when freeing null pointer

(cherry picked from commit e35f30ccb608b930c01646aa8e0fbf6d81f731c4)
Signed-off-by: Markus Blatt <markus@dr-blatt.de>