Merge pull request #24 from take-cheeze/refactor

Refactor and libuv update.
update and support libuv-0.11.22
Merge pull request #25 from take-cheeze/libuv-0.11.22

Update and support libuv-0.11.22.
Fix build
Add UV::TCP#getpeername
Add UV::TCP#getsockname and UV::UDP#getsockname
Update TCP/UDP examples with sockname/peername
refactor getsockname and getpeername
add tests for getsockname and getpeername
Merge pull request #26 from take-cheeze/sockname

Rebase #16.
remove use of flags in autoconf and add pthread to libraries
fix variadic arguments
move handle common method to UV::Handle module and include it in handle sub-class
call mrb_uv_gc in finalization
don't use handle module in FS
add UV.guess_handle
add UV::Semaphore
don't use librt in darwin