More feathers

• Provide a URL to a datasheet for the footprint(s) you are contributing
• An example screenshot image is very helpful
• If there are matching symbol or 3D model pull requests, provide link(s) as appropriate
• Check the output of the Travis automated check scripts - fix any errors as required
• Give a reason behind any intentional library convention rule violation.

This provides additional variations on the Feather footprint from #1657. It also applies some fixes to the original footprint.

I used the original board files from Adafruit to doublecheck the board dimensions and pin placement (by overlaying the new footprint).

Documentation

• https://learn.adafruit.com/adafruit-feather-32u4-fona
• https://learn.adafruit.com/adafruit-feather-m0-radio-with-rfm69-packet-radio
• https://learn.adafruit.com/adafruit-feather-32u4-radio-with-rfm69hcw-module
• https://learn.adafruit.com/adafruit-feather-m0-wifi-atwinc1500/
• https://learn.adafruit.com/introducing-the-adafruit-wiced-feather-wifi

Matching symbols

Some of these footprints are needed by https://github.com/KiCad/kicad-symbols/pull/1933, but I added a few others (32u4_RFM and 32u4_FONA) for completeness.

Policy violations

The FONA footprint says "Courtyard lines are not on 0.01mm grid". This is because that board is 2.375" = 60.325mm long and I just kept the standard 0.25mm or so clearance. What's the recommended way to solve this? Round the board dimensions? Or just the courtyard lines?

3D Models

I just left all of these at the default feather model, since if models are ever added, I'm doubtful that all variants are also added, so then just the default might be better? Or should I just use the footprint name for the 3D models everywhere?

Mounting holes

I noticed that the mounting holes in the original footprint had a slightly different (drill and copper) size than the actual feather boards, so I updated them to match. For the topmost holes, this seems to match all feather boards (Adafruit documentation says "All Feathers have the same two mounting holes near the USB port"). For the bottommost holes, most of them seem to be 2.54mm without plating (checked against the board files of some feathers), so that's what I used for the common footprint. Looking at this incomplete image, there seems to be one that use plated holes and one using 2.2mm holes (ESP8266), but I'm not so sure if it's useful to create all these variations too (also, I'd have to check the board files for each one to see what their hole size is, which I'm not too eager to do). The FONA also uses 2.2mm bottom holes and has its own footprint, so I use 2.2mm in that footprint.

Screenshots of the mounting hole versions