Fixes to be done on da app server

[Konstantina Souvatzidaki]

• IN OFFER INSERTION: replace listing's min_price with the new offer Done with database trigger
• IN LISTING INSERTION: set total_photos value Done on Android
• IN LISTING EDIT: listing name cannot be edited
• IN PURCHASE INSERTION: decrease quantity of listing. If quantity is 0, remove all other offers and the listing itself Not needed cause only one buyer per listing
• IN PURCHASE INSERTION: remove notifications, offers and the listing itself
• IN OFFER ACCEPTANCE: do not remove all other offers here, remove in purchase insertion only
• Server should always be the last one to send a message via socket (not client cause data can be lost)
• IN CREATE LISTING: if the user already has posted a listing with the given name, send error message

Please add more fixes to be done as a comment here if you spot any

[Themelina Kouzoumpasi]

• IN CREATE REPORT: AppServer should send confirmation message (line 755, "CREATE REPORT SUCCESSFUL")

[Konstantina Souvatzidaki]

• Add limit in items returned in LOAD MAIN SCREEN and SEARCH

[Themelina Kouzoumpasi]

• IN ADD_REWARD: AppServer should send confirmation message (line 818, "ADD REWARD SUCCESSFUL")

[Konstantina Souvatzidaki]

• Replace all ' with '' to escape

[Themelina Kouzoumpasi]

• IN CREATE_EVALUATION: AppServer should send confirmation message (line 741, "CREATE EVALUATION SUCCESSFUL")

[Stella Douka]

• IN REMOVE_REWARD: it does not exist
• IN EDIT_LISTING: adding more pictures not supported
• IN EDIT_LISTING: can delivery method be changed? Yes
• IN CREATE_LISTING: send failure message if listing name already exist by the same creator

[Themelina Kouzoumpasi]

• Notification class should have byte[] photo field
• IN REQUEST_NOTIFICATIONS: add photo field in Notification objects, getting thumbnail from bucket