Updated /rsprices on ItemFrame.

[FEATURE] If you right click on an itemframe within 3 seconds since the first click, the frame will display the next page.
[BUG??] right click within the time limit will increase the page even if there are not so many pages. (it could be annoying but I think not, because passed the limit the pages are setted to 1 again)
Updated /rsprices on ItemFrame #2.

Fixed code to avoid hangs and null pointer exceptions.
Updated /rsprices on ItemFrame #3.

Fixed possibile Array out of bound Exception