add skipped cmps options

[lukh]

(follow up of the ticket #302 ) It adds a menu (skip, forward icon) that allows you to add a comma separated list of Ignored Components. It works well when view is not in grouped mode

I have a concern about pcbdata.bom.skipped entri, since in the current state you have to remove the entries in pcbdata.bom.both|front|back (it looks like skipped is not really used, except fr stats mayybe ??) I added a filter in populateTable / entries

[qu1ck]

Sorry, I don't think I can merge this for the following reasons:

1. It doesn't affect grouped view which it intuitively should
2. The feature has a very narrow use case. Usually users will just specify the exclude list at bom generation time.
3. It introduces one more menu to the top row which is already near it's limits in terms of easy UI navigation and what can fit on narrow/mobile displays.

First reason can be fixed, the others not so much. This feature is a perfect use case for the user customization. If you can reformat your change into user* files I'll add this as an example to Customization wiki.