fix @warning preprocessor directive to work in msvc as well

git-svn-id: svn://svn.code.sf.net/p/libtorrent/code@10490 a83610d8-ad2a-0410-a6ab-fc0612d85776
apply Jakob Petsovits' patch for include path order for cmake

git-svn-id: svn://svn.code.sf.net/p/libtorrent/code@10491 a83610d8-ad2a-0410-a6ab-fc0612d85776
merge Jakob Petsovits' patch to separate CMakeLists.txt for examples

git-svn-id: svn://svn.code.sf.net/p/libtorrent/code@10492 a83610d8-ad2a-0410-a6ab-fc0612d85776