Added char limit to connections in database table and form

Line 139 in file TopicPhoto.php
this section of code was making an error when the connection was added so i commented it out for now to get the add connection page to submit successfully.

i worked on issue number 6 : Add character limit to connections
here are the changes i made:
1. database table topic_photos: changed description column type from text to varchar(250)
2. add-photo.ctp file: added “limit: 250 characters” to label variable on line 50

suggestion: fix WideImage function and add validation function to show when 250 character limit is reached on the add connections page.