pythongen: make code more pythonic

[mseri]

There is still an outstanding issue: pythongen imports xapi and storage from xapi-storage. I am going to fix it as well, but it's good to start reviewing the code

[mseri]

The last commit fixes the import thing.

@gaborigloi with this change, in xapi-storage you will have to use

of_interfaces ~helpers:"from xapi import *" interfaces

The example stubs are still xapi and xapi.storage dependent, I am not yet sure how to fix them. Probably they need to be provided by the packages using the library. Not sure yet

[gaborigloi]

Could we add an annotation to e.failure() to make pylint work?

[mseri]

pylint will not work anyway as it does not like the long int syntax and lines longer than 80 characters

[mseri]

I did run pycodestyle on it. With the latest commit the only complaint it has is `E501 line longer than 80 characters"

[mseri]

I was able to run pylint on a buildenv, now the generated python passes pylint as well

[mseri]

And now we don't even need the pylint annotation

[gaborigloi]

We had an issue with the generated code where it was saying that "1423432 does not have type int64". We tried passing both with and without "L".

[mseri]

Can you run another test with the latest changes. I've done some more cleanup and uniformed the module with the main Rpc

[gaborigloi]

The quicktests passed again :)

[mseri]

Let's merge. We can make further cleanups in subsequent PRs if needed