Issue #152
Check if offset [3] exists in capabilitites array:

* Fixes PHP Notice occurring when using a client's custom capability manager plugin
no message
Fix typos in readme.txt
Fix headings check in content analysis
Some code style changes
Fix XML site map appearance by fixing XSL to work properly. Fixes #185.
Fix slug stopwords removal, props @amm350, fixes #182
Merge pull request #171 from mbijon/offset3-empty

PHP Notice logged when site has capabilities created without 3rd value in args array
Update read me for latest pull merge
Merge pull request #153 from MarcQueralt/master

Issue #152
Wrap do_shortcode tags in output buffering to prevent shortcodes that echo stuff instead of return from breaking things like in #190
code style cleanup.
Fix keyword in first paragraph test.
Clean up code style and add missing PHPdoc
Reverting the addition of `do_shortcode` because it clashes with too many plugins that use short codes in a wrong way… Instead added the filter `wpseo_pre_analysis_post_content` to the content for open graph as well, so it can analyze properly added content, but not the wrong stuff.
Add better regex for heading retrieval as suggested by @jrfnl
Update change log for `do_shortcode` reversal
Getting ready for 1.4.15, flushing rewrite rules on upgrade.
Drop unused variables name and url from tracking class.