Support OSX

[neeraj9]

There are certain Gnu/Linux specific api usage which needs to enhanced to support OSX.

Work items:

1. Procedure to setup development environment or alternative libraries available on osx.
2. The socket and polling (or add kqueue support in additional to existing epoll). Alternatively, use another open source project (like libuv) to do that work.
3. Support both clang and gcc on the platform.