Improve check for in-source build.
Updated Boost to version 1.57.0.
Updated CMake if statements in line with CMake v3.1 policy.
Bugfix in add_gtests CMake module.
Merge remote-tracking branch 'origin/next' into MAID-203
Fixed to handle source paths containing regex special chars.
Merge pull request #173 from Fraser999/MAID-500

Updated CMake if statements in line with CMake v3.1 policy.
Merge remote-tracking branch 'origin/next' into MAID-203

Conflicts:
	CMakeLists.txt
Cmake 3.0 fix

Moved add_subdirectory to after if statement
Merge pull request #174 from rossmuir/MAID-511_Cmake_3_fix

Cmake 3.0 fix
Merge remote-tracking branch 'origin/next' into MAID-432_boost_1_57

Conflicts:
	cmake_modules/add_boost.cmake
Merge remote-tracking branch 'upstream/next' into MAID-432_boost_1_57
Added "CheckXXX" target to each submodule.
Merge pull request #169 from Fraser999/MAID-432_boost_1_57

Updated Boost to version 1.57.0.
Merge pull request #146 from Fraser999/MAID-203

MAID-203: Improve check for in-source build.
Added standalone (non-Boost) Asio.
Added Boost.Expected.
Merge pull request #178 from Fraser999/MAID-534

Added standalone (non-Boost) Asio.
Couple of bugfixes for CMake code.
Merge pull request #179 from Fraser999/MAID-534_bugfix

Couple of bugfixes for CMake code.