Apply pep8 rules in api and www/views [v2]

[caiocarrara]

Most of the changes are simple indentation and blank lines spaces. There was also some import fixes that shuldn't change any behavior.

Probably the biggest change was in the method has_permission() of PatchewPermission class (api/rest.py). Firstly the use of backslash inside braces is redundant (to break lines). So in order to remove the backslashes and trying to make the permission conditions more readable I've tried the following approach.

It was also necessary to fix the help_text attributes of Project model fields. The way the help text strings were being used in Project model attributes was putting a lot of whitespaces and line breakes inside them[1].

If these changes be accepted I'm willing to continue applying it on other files.

[1] - more details in commit message

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Changes from v1[#95]:

• Squash commits related with PEP8 specifically;
• Fix minor bug added in get_diff_stat method from Message model;
• Fix help_text attribute from Project fields

[bonzini]

Looks good, I'll wait for Fam to give it another look and then push.

[famz]

@bonzini let's use the next branch from now on (which is synced to next.patchew.org).

@cacarrara Please rebase to next branch where there is a migration conflict.

[caiocarrara]

@famz rebased to next :+1: