* When editing a sketch post, the plugin will automatically give users editing choice (will change this so that a choice is presented if there's more than one image attachment)
* Saving edits will now overwrite the original file (should probably provide options to turn this on or off)
* Editing file only works with .chi files, need to implement loading from images
* Submission results page is copied into a div, easier to deal with but needs to be tested for any performance issues
* canvas initialization has been made into a function