A wiki article pointed out that whitespace will only be preserved for parameters
in CMake commands if passed strings will be appropriately quoted or escaped.
http://cmake.org/Wiki/CMake/Language_Syntax#CMake_splits_arguments_unless_you_use_quotation_marks_or_escapes.
Quoting was added so that more places should also handle file names correctly
which contain space characters or semicolons eventually.
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
The CMakeLists.txt adds -std=c++11 and related compiler flags, but looses default flags specified by CMake build type.
For example, -DCMAKE_BUILD_TYPE=Debug has no effect, as -g flag gets lost.
By adding headers to sources of targets, CMake adds them to list of project files generated for IDEs.
This is non-intrusive trick, which does not affect targets compilation.
