some minor changes to make the build run with python 3

[DaanHoogland]

Description

print as method
async keyword use in variable name fixed
urllib openurl from urllib2 to urllib.request

This PR covers partially issue #3195.

Types of changes

• Breaking change (fix or feature that would cause existing functionality to change)
• New feature (non-breaking change which adds functionality)
• Bug fix (non-breaking change which fixes an issue)
• Enhancement (improves an existing feature and functionality)
• Cleanup (Code refactoring and cleanup, that may add test cases)

Screenshots (if appropriate):

How Has This Been Tested?

[nvazquez]

@DaanHoogland in my tests compile and run works fine, but I'm having this problem with the marvin deploy script:

$  python tools/marvin/marvin/deployDataCenter.py -i ../adv-kvm.cfg
  File "tools/marvin/marvin/deployDataCenter.py", line 77
    print "\n=== Data Center Settings are dumped to %s===" % dc_file_path
                                                         ^
SyntaxError: Missing parentheses in call to 'print'. Did you mean print("\n=== Data Center Settings are dumped to %s===" % dc_file_path)?

[nvazquez]

This will need refactor in many places, maybe considering this library? https://docs.python.org/2/library/2to3.html

[DaanHoogland]

yes @nvazquez this only addresses the build. There is another PR out for python3 changes (#3730 by @GabrielBrascher) for the system vm. I don't want to merge, as this is kind of independent. I did hit that deploy script as well, we can put that in a separate PR. or here as well, i just want to move this quickly and smaller chunks move faster ;)

[GabrielBrascher]

Thanks for the PR @DaanHoogland. Always looking forward for PRs porting Python2 to Python3 :-)

[GabrielBrascher]

@DaanHoogland shouldn't the header of this python file be changed from #!/cygdrive/c/Python27 to #!/cygdrive/c/Python3?

[GabrielBrascher]

Sorry if this comment is redundant, I see that @nvazquez mentioned about changing other pieces as well.

[DaanHoogland]

I think the cygwin specific python is not a good idea in any case #! /bin/env python would be better.
I think this is being taken into account in ther PRs so maybe i should close, @nvazquez @GabrielBrascher ?

[DaanHoogland]

The changes here are in #4479 as well, will probably close this one.