Fixed TypeError in TcpHandle and sign_pythonrsa

[YSunLIN]

See #86

In Python3, using str as the type of _buf causes TypeError: Can't convert 'bytes' object to str implicitly in the newest commit 0b15f4f with python-rsa.

  File ".\adb.zip\__main__.py", line 210, in <module>
  File ".\adb.zip\__main__.py", line 206, in main
  File ".\adb.zip\adb\common_cli.py", line 149, in StartCli
  File ".\adb.zip\adb\adb_commands.py", line 138, in ConnectDevice
  File ".\adb.zip\adb\adb_commands.py", line 169, in _Connect
  File ".\adb.zip\adb\adb_protocol.py", line 320, in Connect
  File ".\adb.zip\adb\sign_pythonrsa.py", line 69, in Sign
  File "E:\Python\Python3\lib\site-packages\rsa\pkcs1.py", line 272, in sign
    hash = _hash(message, hash)
  File "E:\Python\Python3\lib\site-packages\rsa\pkcs1.py", line 346, in _hash
    hasher.update(message)
  File ".\adb.zip\adb\sign_pythonrsa.py", line 29, in update
TypeError: Can't convert 'bytes' object to str implicitly

And it can be fixed below:

   # hashing algo for this.
   class _Accum(object):
     def __init__(self):
 -     self._buf = ''
 +     self._buf = b''
     def update(self, msg):
       self._buf += msg
     def digest(self):
       return self._buf

And thanks to @Myonium, the TypeError in TcpHandle can also be resolved.

@fahhem I don't know why this PR cannot be accepted. If you guys don't want to merge this branch, just close it.

[coveralls]

Coverage remained the same at 42.691% when pulling 9a0a928 on YSunLIN:master into 0b15f4f on google:master.

[coveralls]

Coverage remained the same at 42.384% when pulling d26c3d5 on YSunLIN:master into ee2d54e on google:master.

[fahhem]

Hmm, this seems to cause problems with the USB handle. It seems the TCPHandle needs to convert to bytes in the right place, because the signing libraries should only see binary data, not unicode.

[YSunLIN]

@fahhem I opened the issue #86 and then made a pull request #89 to fix the problem.
I also merged the @Myonium's TcpHandle solution to which you agreed.
However, you merged #97 and ignored this PR until now.
I don't know if it is discrimination or not.

[fahhem]

Lol, not discrimination, I just come back to this project on and off and don't necessarily remember all the things every time (nor do I go through all the issues every time).

Well, hopefully it works now for USB and tcp! If you'd like credit you can add yourself to the CONTRIBUTORS file in another PR, I'll gladly merge it since you've contributed via issues as well as code.

[YSunLIN]

Thanks for your prompt reply. And I will continue contributing to this repo.

[fahhem]

Thanks!