Set commentstring in pymode_options.

This setting is used in vanilla vim for adding fold markers, but also by
vim-commentary for using the appropriate comment marker for specific
filetypes.
Update documentation regarding commentstring.
keyword match pythonClass
fix Chinese runtime error

fix Chinese runtime error
Fix typo in option filtering

This also fixes an error where pymode_lint_ignore was not interpreted
correctly anymore.
Update pylama
Update autopep8
Merge pull request #214 from winged/develop

Fix typo in option filtering, causing possible syntax error
Merge branch 'develop' of github.com:klen/python-mode into develop
Merge pull request #203 from loyalpartner/develop

fix Chinese runtime error
Merge pull request #198 from dkasak/commentstring

Set commentstring in pymode_options.
Merge branch 'develop' of github.com:klen/python-mode into develop
Added AUTHORS file.
Update version.
Merge branch 'release/0.6.17' into develop
Refactoring code checking
Merge branch 'feature/rope' into develop
Several improvements

Added option 'g:pymode_syntax_highlight_equal_operator'
If set, assignment '=' operator is highlighted

Added option 'g:pymode_syntax_highlight_stars_operator'
If set, star '*' and double star '**' operators are highlighted

Added option 'g:pymode_syntax_highlight_self'
If set, 'self' and 'cls' are highlighted as keywords

Added option 'g:pymode_syntax_builtin_types'
If set, all built-in types are highlighted
Some types like 'file' and 'super' were declared previously as built-in
functions, but in reality they are also types.
Fix error on non-ascii characters in docstrings

Fix for issue #211: 'Non-ascii characters in docstrings trigger unicode
error'. Use _get_encoding to encode docs in show_doc.
Use _get_encoding for other instances of encode