updated gfs block

[davidefa]

ver2.2
I have updated the gfs block to show the maps again ( as maps were disabled in version 2.1 )

ver2.3
added an option to limit the number of 'runs' visualized ( as runs 33 and 34 generally screw up everything )

ver2.4
- fixes due to changes in source
- added option to show cumulative rain or 'instant rain'

[RobRead]

added "Southern Hemesphere"

inserted

<option value="polar"><?php echo lang('southern hemisphere','c')?></option>
<optgroup label="<?php echo lang('australasia','c')?>">
<option value="australia" selected><?php echo lang('australia','c')?></option>
<option value="new_zealand"><?php echo lang('new zealand','c')?></option>
</optgroup>

above
<option value="polar"><?php echo lang('northern hemisphere','c')?></option>

and altered
else{
return "polar";
}

to
else{
return "australia";
}

to select Australia as default.

[Daali]

You 2 dudes are killing it!. Thank you both for your work

[Julius]

This block has an issue not showing minus zero degrees values (when the windrose block is used?)