Delete empty mojo python package, and prefix all python packages with mojo_

mojo/public/python/c_async_waiter.pxd

 # Copyright 2014 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 # distutils: language = c++
 
 from libc.stdint cimport intptr_t, uint32_t, uint64_t
 
 
 cdef extern from "mojo/public/c/system/core.h" nogil:
   ctypedef uint32_t MojoHandle
   ctypedef uint64_t MojoDeadline
   ctypedef uint32_t MojoHandleSignals
 
 
 cdef extern from "mojo/public/c/environment/async_waiter.h"  nogil:
   ctypedef intptr_t MojoAsyncWaitID
 
 
 cdef extern from "mojo/public/python/src/common.h" \
     namespace "mojo::python" nogil:
   cdef cppclass PythonAsyncWaiter "mojo::python::PythonAsyncWaiter":
     PythonAsyncWaiter()
     MojoAsyncWaitID AsyncWait(MojoHandle,
                               MojoHandleSignals,
                               MojoDeadline,
                               object)
     void CancelWait(MojoAsyncWaitID)