issue-6: make function that is run on content_save_pre for filtering content
issue-6: parse $content to get data-mentionable
issue-6: properly put mentioned ids into array
issue-6: clean up formatting
issue-6: put in some debug code to figure out what's up with post saving
issue-6: preperly save mentioned_by in remote post (requires double publish on original post, why?)
issue-6: lots of cleanup for phpcs
issue-6: use $post_id passed in callback instead of globalizing $post
issue-6: remove object check now that we're not globalizing $post
issue-6: remove debug code
issue-6: use absint intead of numeric to check results
issue-6: use $this instead of self::
issue-6: remove unused function
issue-6: make save_post take 3 args
issue-6: make update_mention_meta take 3 args
issue-6: in update_mention_meta check for update
issue-6: make get_mentioned_ids check for input properly
issue-6: switch from post_updated to save_post
issue-6: add assertion for save_post action
issue-6: move var creation above test
issue-6: making my mark
issue-6: first iteration of mentionable-postmetas.php  DOES NOT WORK
issue-6: abstract post meta functions to another class
issue-6: put test into get_mentioned_ids to make sure we get good data
issue-6: change the way the post meta object is instantiated
issue-6: adjust unti test to reflect new object
Refactor when class are called
issue-6: make it so that UNmentioned posts get removed from their post meta
issue-6: set up tests for actions in constructor
Merge pull request #9 from x-team/issue-6

Issue 6, store mentioned data in post meta closes #6
Merge conflict