add RJ45 ethernet connector Pulse JXD6-0001NL

[hvraven]

This adds a ethernet magjack from Pulse (datasheet). Symbol is based on the existing Würth 7499010121A. Matching footprint in KiCad/kicad-footprints#1887

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All contributions to the kicad library must follow the KiCad library convention

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 symbol(s) you are contributing
• An example screenshot image is very helpful
• Ensure that the associated footprints match the official footprint library
  • A new fitting footprint must be submitted if the library does not yet contain one.
• If there are matching footprint PRs, provide link(s) as appropriate
• Check the output of the Travis automated check scripts - fix any errors as required
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[cpresser]

Looks good. I like that you connected the shield in the symbol.
One thing I would like to see improved is description/keywords.

• There is no mention of the fact that this is a magjack.

edit I just realized it says 'transformer'. Which is good enough, all the other similar parts have the same keywords. And Magjack is a trademark after all.