deps: update libuv to v0.11.23
src: update uv callbacks after API changes

async, timer, prepare, idle and check handles no longer get a status
parameter since they can never fail.
src: fix use of uv_cwd, len includes the NULL byte
path: fixed regex for extname() in win32
path: fixed regex for extname() in win32. added test.
Merge branch 'issue7386' of github.com:roryrjb/node into issue7386