[feladat @ 156] Made a lot of small changes to allow PHP to run with error_reporting E_ALL without giving notices. Most functions have been checked but some situations might give a notice.

[feladat @ 127] Bugfix for ticket:5 : Modified the query which searches zones to also find empty zones by adding a LEFT JOIN.

[feladat @ 124] Minor bugfix. If number of zones exceeded maximum row amount and the '0-9' was selected to be shown, the '0-9' was not rendered in bold, where in all other cases the selected letter is shown in bold.