Libpmemobj-cpp Version 1.6

This release introduces ctl support, allocation flags, snapshot
method and new experimental persistent container - vector.

New features:

• add support for pmemobj_ctl_set/get/exec
• expose allocation flags in make_persistent(_atomic)
• transaction: add snapshot method

Experimental features:

• persistent vector container

Other changes:

• automatically start transaction inside pmem::obj::experimental::array
  modifier methods (assignment operators, swap and fill)
• add const methods for pmem::obj::experimental::array
• add Valgrind instrumentation support
• remove experimental const_contiguous_iterator
• add get with arguments method overload for v

Bug fixes:

• throw an exception when dropping pmem lock failed
• fix crash when previous transaction failed to start
• fix forwarding parameters to constructor in make_persistent_atomic

Optimizations:

• decrease number of persistent_ptr dereferences in
  make_persistent_array