installation: dependency links renovation

* Prepares `setup.py` for Invenio v2.0 release for pip<1.6.
  (addresses #1797)

* NOTE use `pip install --process-dependency-links -e .`

Signed-off-by: Jiri Kuncar <jiri.kuncar@cern.ch>
formatter: fix Bibfmt model import

* Fixes broken import of `Bibfmt` model.  (closes #1781)

Signed-off-by: Jiri Kuncar <jiri.kuncar@cern.ch>
legacy: fix javascript on /record/edit

* Addresses issue with record editor not loading record data.
  (closes #2143) (PR #2178)

Co-authored-by: Jiri Kuncar <jiri.kuncar@cern.ch>
Signed-off-by: Petr Broz <petr.broz@gmail.com>
legacy: fix broken import to create_record

Signed-off-by: Jiri Kuncar <jiri.kuncar@cern.ch>
deposit: minor edit action bar fix

Signed-off-by: Lars Holm Nielsen <lars.holm.nielsen@cern.ch>
communities: ckeditor toolbar changes

* Adds Mathjax support to CKEditor and removes certain other buttons.

Signed-off-by: Lars Holm Nielsen <lars.holm.nielsen@cern.ch>
base: missing MathJax config variable

* Adds missing config variable CFG_MATHJAX_RENDERS_MATHML to default
  configuration.

Signed-off-by: Lars Holm Nielsen <lars.holm.nielsen@cern.ch>
formatter: master merge fix

* Reapplies 71fe41cacf6bdb124433aca1a40acafdeaf361af which got
  overwritten by the large master to next merge.

Signed-off-by: Lars Holm Nielsen <lars.holm.nielsen@cern.ch>
formatter: format record extra context fix

* Fixes issue with passing extra context variables to format record
  introduced during merging new changes from master.

Signed-off-by: Lars Holm Nielsen <lars.holm.nielsen@cern.ch>
bibupload: support for strings in utils

* Adds support for strings instead of only recstruct in
  bibupload_record helper function.

Signed-off-by: Lars Holm Nielsen <lars.holm.nielsen@cern.ch>