Screenshot class cleanups. Move screenshot related functions into the class. Rename get_screenshot_img() to

get_random_screenshot_img() so the name of the function matches its purpose

include/application.php

@@ -545,7 +545,7 @@ class Application {
         }
 
         // image
-        $img = get_screenshot_img($this->iAppId);
+        $img = Screenshot::get_random_screenshot_img($this->iAppId);
         echo "<tr><td align=\"center\" colspan=\"2\">$img</td></tr>\n";
     
         echo "      </table>\n"; /* close of name/vendor/bugs/url table */