Øystein Blixhavn

* Adds option scrollContainer to use if the sidebar is contained in a parent div with fixed height and overflow-y: scroll/auto solves #107

As demonstrated in https://codepen.io/blixhavn/pen/dyPMYeM When wrapping the sidebar and its content within a scrollable, fixed-height div, the sticky sidebar does not work.

BibCirc: Inserted JS redirects user on key press when a book is returned

2

This was [added intentionally in 2010](https://github.com/inveniosoftware/invenio/commit/388d4d6f2ff5c7658b18875ba9029df1e00feacc) ([line 1562](https://github.com/inveniosoftware/invenio/commit/388d4d6f2ff5c7658b18875ba9029df1e00feacc?diff=unified#diff-e3552d06a2abeffc30d84cfca271884cR1562)) , but it disables effective return of several books. I propose that we remove this.

### What problem are you facing? While this repository is adequately documented on how to develop your own provider, I feel like we're on our own when it comes to...