Converted update screensaver script to represent pattern in a JSON form.

Since this was to be edited by the customer, this has been made simple, whilst reducing issue casued by
 the reliance on splittng the patterns using two newline characters(Support #183)
Merge pull request #80 from CO600GOL/bug/#187_screensaver_mode_exception

Converted update screensaver script to represent pattern in a JSON form.