LimeSDR v1.4s Case

This is a 3D printed case for the LimeSDR v1.4s variant. It has been remixed from this design: http://www.thingiverse.com/thing:2160863.

Added the following enhancements:
- Modified to properly fit the LimeSDR v1.4s variant
- Added heat dissipation grills
- Exposes up to 12x SMA connectors with easy to mount non-turning cut-outs
- Added option for CLK_IN and CLK_OUT
- Labels under each connector

Tips:
- Use U.FL to SMA cables with length of minimum 15cm
- Mount the U.FLs with care on the board.
- Due to limited U.FL lifetime, avoid multiple snap-ins/snap-outs