finished functionality for loading a list of all tags in the tags table
fixed error with image path upload, finished checkboxes for assigning tags to an ad
completed Tag Object constructor method.need to add method to create a new tag
fixed error in addImage method, changed image path filter to sanitize url, added ability to add tags to a created add, need to fix update method to allow changing of tags
removed attempt at ad_manager save() method, moved method to ad class
added buttons for each tag associated with the ad being viewed
removing unnecessary method, adding comments on new methods