added Alps EC11 and EC12 rotary encoder footprints

[jkriege2]

• made to match generic symbols from device.lib (see also reworked rotary encoder symbols kicad-symbols#206)
  
• variants with and without switch
• for now 20mm shaft lengtrh variants (given height for future 3D models, variants with other shaft lengths can come in future)
• variants with circular holes for mounting-pins
• mounting pins are assigned pin0 to allow connecting them to a shield explicitly with symbols from reworked rotary encoder symbols kicad-symbols#206
• datasheets:
  • http://www.alps.com/prod/info/E/HTML/Encoder/Incremental/EC11/EC11E15204A3.html
  • http://www.alps.com/prod/info/E/HTML/Encoder/Incremental/EC12E/EC12E1240405.html
  • http://cdn-reichelt.de/documents/datenblatt/F100/402097STEC12E08.PDF
• cross marks axis center on F.Fab and F.Silks

check against 3D models from ALPS: EC11

These images show that the ALPS models fit the footprints:

check against 3D models from ALPS: EC12

These images show that the ALPS models fit the footprints:

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Thanks for creating a pull request to contribute to the KiCad libraries! To speed up integration of your PR, please check the following items:

• Provide a URL to a datasheet for the footprint(s) you are contributing
• An example screenshot image is very helpful
• Check the output of the Travis automated check scripts - fix any errors as required

[poeschlr]

Take a closer look at the silk outlines. Some of them are "behind" the fab outline instead of being outside of it.
From the 3d models it looks like the pads that currently have number 0 are there to increase the mechanical strength. So i think these should get pin number "MP" as decided in issue #117

The landing patterns look ok.

[jkriege2]

I fixed the silkscreen-problems (only found two in the EC11E's).

ABout the pin-naming, @evanshultz raised comparable question at the PR for the symbols: KiCad/kicad-symbols#220 ... I think we should discuss that there and I will change both PRs, depending on the outcome of that discussion.

[jkriege2]

rename pin 0 to pin MP as explained over in KiCad/kicad-symbols#220

[jkriege2]

@poeschlr @evanshultz Since the symbols have been merged with KiCad/kicad-symbols#220 ... Could I get a review for these?

Thanks,
JAN

[poeschlr]

Sorry this has been forgotten for so long. Looks good now. Thanks