Merge pull request #27 from take-cheeze/refactor

Split mrb_uv.c to few files.
Remove compiler warning
Fix build
status argument in callbacks was removed in latest libuv
ditt
Remove compiler warning
Remove compiler warning
Remove compiler warning
Remove compiler warning
status parameter of Timer/Idle/Prepare/Async were removed in latest libuv
Fix test for UV::Pipe on windows
Fix test for UV::Pipe
Fix test of UV::Pipe
Fix test on windows
Make shared library functions public to mruby/uv.h .
Merge pull request #28 from take-cheeze/mruby_uv_h

Make shared library functions public to mruby/uv.h .
Fix wrong operator.
Check closed (disposed) object when getting pointer.
Clear pointer before free.
Move mrb_module_get workaround to mrb_uv.h .