insert_gap() method worked incorrectly. It used std::move_backward to move
elements in a vector, ignoring the fact that memory after size() was uninitialized.

This resulted in operator= being called on uninitialized elements instead of
copy/move constructor.

Fix this issue by reimplementing insert_gap as internal_insert. Use generic
implementation for iterators to implement all cases.

and change name of construct_range_copy to construct.

conctruct_range can be implemented using construct_range_copy by passing
std::make_move_iterator(iterator) as parameters.

string: modifiers

Make valgrind build separate travis step

It's done for build time optimization.

* Put builds as separate functions in run-build.sh
* Explicitly list, which builds should be run according to build type
* Add valgrind build type
* Add valgrind build as separate travis step

Add concurrent_hash_map_pmreorder_break_insert test

Add simplekv example

Add concurrent_hash_map_pmreorder_erase test

Add flags to disable warning C4996

Fix warnings C4800: 'int': forcing value to bool

Add concurrent_hash_map_pmreorder_insert_erase_mt test

Add flags:
 -D_SCL_SECURE_NO_WARNINGS to disable checking iterators
 -D_CRT_SECURE_NO_WARNINGS to disable deprecation of getenv and strcpy functions

It disables 156 such warnings.

Ref: #409

Correct small misspell in pman's Game Over message

It fixes 503 warnings #C4800.

Ref: #409

and rebuilds rest on application restart.

Decrease Visual Studio warning level to W3

appveyor: msbuild: set verbosity to minimal

... to reduce the Appveyor build time.

... to reduce the Appveyor build time.

appveyor: set PMEM_IS_PMEM_FORCE in tests

PMEM_IS_PMEM_FORCE is not set in tests
and Appveyor build is timed out.

Appveyor: switch to Visual Studio 2017

This change is required because of the following issue:
https://help.appveyor.com/discussions/problems/24684-problem-with-vcpkg-wrong-version-on-appveyor
https://github.com/appveyor/ci/issues/3052
which cannot be fixed directly now.

Concurrent hashmap: removal of atomic allocation support and minor refactoring

Ref: https://github.com/pmem/libpmemobj-cpp/issues/356

Atomic allocator has limited use case since pmemobj does not allow
for nesting make_persistent_atomic calls.

To make it obvious what is the layout of the structure.

Fix concurrent_hash_map_pmreorder_multiple_buckets test