unify usage of get_pool()

Singlethreaded radix tree implementation

Also, add doc snippet (BytesView example) to radix_tree.

It reads a sequence of keys from stdin and prints radix in a DOT
format.

Based on: https://github.com/pmem/pmdk/blob/master/src/libpmemobj/critnib.h

It is a data structure that holds sequence of chars within the same
memory as the inline_string data structure itself. It requires
custom allocation logic and a runtime wrapper (accessor) which
is aware of the memory location and capacity.

Exclude self_relative_ptr from installation files

Implementing self-relative pointer

Enable libcxx swap tests

Enable map modifiers tests

Update ndctl

Enable few map.modifiers tests

doc: treat doxygen warnings as errors in developer mode

Add missing operators to detail::pair<> required by libcxx tests

@param should not be used multiple times for the same argument.

doc: add examples/ to EXAMPLE_PATH in doxyfile

concurrent_map: fix typo

Without this, doxygen cannot find doc snippets from examples.

added simple example for string

Add missing constructor to concurrent map

Fix clang format lookup

on Ubuntu it's called "clang-format-9" not "...-9.0".

Add missing constructor
Enable compare.pass test

update docker containers version to 1.11

LIBCXX map tests: CONS