There is no reason for examples to be under bibstuff module
BF: adjusting scripts for bibstuff being a module now + chmod +x them
NF: bibmatching directive to include all references matching a set of filters

E.g.

.. bibmatching:: example.bib
    :style: demo
    :filter:
       author: \bTheGod\b
       howpublished: \b(Talk|Poster)\b
    :sort:

should only list Talks and Posters from TheGod .

Additional sugarings:

- any key could be specified.  If empty, e.g.

  :filter:
    : God

  then it should look through all the fields

- if any (or all) letters in the field name is uppercased -- search will
  be case-sensitive

- if field name is prepended with '!' -- ignores the effect and only
  non-matching entries would be considered, e.g.

.. bibmatching:: example.bib
    :style: demo
    :filter:
       author: \bTheGod\b
       !howpublished: \b(Talk|Poster)\b
    :sort:

  should complement publications from TheGod to previously included query.
Merge remote-tracking branch 'yarik-onerussian/master'

* yarik-onerussian/master:
  NF: bibmatching directive to include all references matching a set of filters
  BF: adjusting scripts for bibstuff being a module now + chmod +x them
  There is no reason for examples to be under bibstuff module