Add amenity=clock into presets

[AlfonZ]

I have created preset for amenity=clock based on wiki. I'm not sure though, if visibility tag description is appropriate/accurate.

<item name="Clock" icon="presets/empty.png" type="node">
    <link href="http://wiki.openstreetmap.org/wiki/Tag:amenity=clock"
          de.href="http://wiki.openstreetmap.org/wiki/DE:Tag:amenity=clock" />
    <label text="Edit Clock" />
    <key key="amenity" value="clock" />
    <optional>
        <combo key="display" text="Display" values="analog,digital,sundial,unorthodox" default="" delete_if_empty="true" />
        <combo key="support" text="Support" values="pole,wall_mounted,billboard,ground" default="" delete_if_empty="true" />
        <combo key="visibility" text="Visibility/readability" values="house,street,area" display_values="(up to 5m),(up to 20m),(more than 20m)" default="" delete_if_empty="true" />
        <check key="date" text="Shows current date" default="off" delete_if_empty="true" />
        <check key="thermometer" text="Shows temperature" default="off" delete_if_empty="true" />
        <check key="barometer" text="Shows barometric pressure" default="off" delete_if_empty="true" />
        <check key="hygrometer" text="Shows humidity" default="off" delete_if_empty="true" />
    </optional>
</item>

[ulfl]

fixed in svn 3572