Fix comment to refer to sample/include.am correctly
Fix harmless clang enum warning
When EWOULDBLOCK is not EAGAIN, treat it as equivalent to it

Acording to http://stackoverflow.com/questions/7003234/which-systems-define-eagain-and-ewouldblock-as-different-values
there are some older unixes that distinguish these error.s
Fix typo : Dispatching instead of Dispaching