Add C++11/C++14 discussion, clarify 32-bit vs. 64-bit for Windows

Add links to some pages on Wikipedia and cppreference to highlight the
new elements in C++11/C++14 and the support in compilers for them.
Remove some incorrect language about Visual Studio Express not being
able to generate x64 binaries.
Remove links to prebuilt 64-bit Windows Boost binaries because the CMake
recipe generates 32-bit solutions/projects for Visual Studio.