Add UV_RUNTIME_CHECK() macro to print uv_strerror()

Add UV_RUNTIME_CHECK() macro to print uv_strerror()

When libuv functions fail, they return correct return value that could
be useful for more detailed debugging.  Currently, we usually just check
whether the return value is 0 and invoke assertion error if it doesn't
throwing away the details why the call has failed.  Unfortunately, this
often happen on more exotic platforms.

Add a UV_RUNTIME_CHECK() macro that can be used to print more detailed
error message (via uv_strerror() before ending the execution of the
program abruptly with the assertion.