Adding new statistics and bugfixes
Fix identation
Trying to remove top-key from critical path
Multiple improvements and changes to the extended statistics

* Added COW/CAS based flush

* Trying to reduce the number of accesses to thread-local variables

* Avoid asking to ManagementFactory for ThreadMXBean

* Avoid creating the log class multiple times
Remove flusher thread and adde cooperative flush
Fixed top-key collection
Added new statistics and control over it

* New statistics to collect the waiting time in GMU queue

* It is possible to disable/enable the statistics in runtime and to
enabled/disable the GMU queue waiting time independent
IGNORE_RETURN_VALUES support for GMU
Added other test case for IGNORE_RETURN_VALUES flag
Fix CCE in update contentio (lock wrapper)