Squashed 'src/websocketpp/' content from commit 802e34b

git-subtree-dir: src/websocketpp
git-subtree-split: 802e34bd2cad95c7ac93acf189813395481e41c9
Merge commit '8fd0707ffb7a3c9174e9852575ac9dbe93f47b12' as 'src/websocketpp'