Customizable Heart shaped box

[**Edit** reworked for adjustable base and lid thickness. Feels better with more weight.]

This box modified from Kit Wallace's github.
- https://github.com/KitWallace/openscad
- http://www.thingiverse.com/kitwallace

**Added:**
- Dimensions
- Option to show Cross section to see fit.
- Overlaps calculated for F6 stl creation