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
Move uv handles code to handle.c .
Separate uv_context to reduce memory use.
Clear DATA_PTR of FS when close.
Implement correct mrb_uv_fs_fd.
Move thread codes to src/thread.c .
Implement dynamic library methods.