Added the ability to edit posts

Added very handy method: Post@loadProperties which loads all properties from
property tables and makes them accessible as instance variables by title
    eg. $post->animal_name will get the content column from the properties table
        where the title column = 'animal_name' for this post

Updated most post_views to allow the post to be editted properly

Added updateRules protected variable to BasePostValidator to allow different
rules to be used for regular creation and updating