PEP257 on pywikibot folder part II

files: family, fixes, i18n and interwiki_graph
Checked by hand and added some suggestions based on this change:
I910fdd7ce36752fa44b9a6654d7b8509e5020dee

Also revoved RversionTab which is not needed:
1- Never been used in pywikibot
2- Related to wikis without API support see lines 1032-1040 in wikipedia.py in compat
Change-Id: I1fb9267828d68743d0a4a8533d7b0433e7205ac6
Merge "PEP257 on pywikibot folder part II"