Parametric Sponge Holder

I absolutely enjoy the [Kitchen Spongeholder](https://www.thingiverse.com/thing:2494514) design by _pdiqlosis_. However, not all the sponges and sinks are created equal. This is why I created a parametrizable version.

Bonus feature: you can choose on which side do you want the drain hole. Of course, you can still use the "mirror" action of your slicer to put the drain hole on the correct end of the chosen side (or simply ask me to add one more customization)


Change Log
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**10.09.2019** — added a possibility to enable or disable the drain duct (i.e. you can just have a hole without a duct)