Add a warning for possible direct access to $wp_query->query_vars

Also attempt to differentiate between ->set() and ->get().
Fixes #61
Add 0.8 Changelog entry to readme.md
Add usage instructions to readme.md and readme.txt
Make `wp vip-scanner analyze-theme --depth=0` really show all hierarchy levels
Remove ThemeSupportCheck

That check was backwards, directly contradicting DeprecatedFunctionsCheck.
In readme.md and readme.txt, replace 'WordPress.org Theme Review' by 'WP.com Theme Review'
Merge pull request #215 from ockham/rm-theme-support-check

Remove ThemeSupportCheck, as it references deprecated WordPress functions. See #214.
Remove TimThumbCheck.

Using TimThumb is not allowed, and this is checked by the
ForbiddenLibrariesCheck. See #214.
Remove ThemeArtisteerCheck

This check is no longer needed, as this will be caught during any other
check or at the latest during a first look through by a reviewer. See
#214.
Remove WormCheck

This is an edge case that will be caught by the reviewer.
Remove WhitespaceCheck

This check is no longer needed.
Merge pull request #211 from ockham/queryvars

Add a warning for possible direct access to $wp_query->query_vars
Merge pull request #213 from ockham/wp-cli-analyze-theme-depth-zero

Make `wp vip-scanner analyze-theme --depth=0` really show all hierarchy levels
Merge pull request #212 from ockham/readme

Add usage instructions to readme.md and readme.txt