Update control flow recommendation message

See 2740609a0fe0e58eb9f124f02960f4c05ba80795 and #185.
Merge pull request #200 from lee-dohm/message

Update control flow recommendation message
fix typos in README
Merge pull request #201 from nikai3d/patch-1

fix typos in README
Port BlockComments to Parser 2.0
Remove redundant message check
Fix a broken example
Make def parentheses checks class methods aware
Extract config into methods
Make the max number of allowed args configurable
Use Parser::Base#tokenize instead of patching Parser::Lexer#advance.

We can remove some code for functionality that is now available
in Parser.
Provide file name to Parser to get better error messages.
Let Parser do the reading of files.

Instead of reading files into strings in RuboCop, we let Parser::Source::Buffer read the files. This decreases duplication of functionality.
Remove the Position class and use Parser's Range class instead.
Get comments directly from #tokenize.

We don't need to extract comments from the array of tokens after a fix
in parser-2.0.0.beta2.
Parse spec example code in memory rather than from temporary file.
Merge pull request #202 from jonas054/review_comments

Fixes based on review comments
Change name of Rubocop::Config.validate! to validate.

This is not a more dangerous version of another validate method so
there should be no exclamation point.
Merge pull request #203 from jonas054/ditch_exclamation_point

Change name of Rubocop::Config.validate! to validate.
Update Changelog for 0.8.0