Py3 Fixes

[s0undt3ch]

What does this PR do?

Py3 fixes for the file state module (and some more minor stuff)

[ninja-]

@s0undt3ch great stuff. I am running python3 on prod. for a while and I monkey-patched some of these issues you are fixing right now.
In particular

• if 'salt' in fp_.read()
• chmod octal encoding

Btw...the worst non-fixed yet py3 bugs(I need to make a list) I remember are:

• some compatibility crash that makes salt-master hang on $ systemctl restart salt-master
• failed to import highstate_return cause of StringIO

2017-02-12 02:30:59,503 [salt.utils.process][ERROR   ][1171] An un-handled exception from the multiprocessing process 'Maintenance-6' was caught:
Traceback (most recent call last):
  File "/usr/lib/python3.6/site-packages/salt/utils/process.py", line 644, in _run
    return self._original_run()
  File "/usr/lib/python3.6/site-packages/salt/master.py", line 243, in run
    self.handle_key_rotate(now)
  File "/usr/lib/python3.6/site-packages/salt/master.py", line 309, in handle_key_rotate
    secret_map['secret'].value = secret_map['reload']()
  File "<string>", line 11, in setvalue
TypeError: bytes expected instead of str instance

[s0undt3ch]

Go Go Jenkins!

[ninja-]

@s0undt3ch I fully tested your PR and now I am running it on production with no problems with python3
👍

[s0undt3ch]

Production? You are brave!!!

[ninja-]

😄

[ninja-]

[cachedout]

@s0undt3ch Just one lint error to be looked at, please: https://jenkins.saltstack.com/job/PR/job/salt-pr-lint-n/8525/violations/file/salt/netapi/__init__.py/

[s0undt3ch]

Fixed.