Sensible default settings for "Enable save actions" and "Cleanup"

[koppor]

The old clean up dialog contained sensible defaults. The current "save actions" in the database properties dialog seem to be different.

Originial dialog:

Current default settings- when clicking "reset" at the Database properties dialog:

This differs from the global defaults:

This should be made consistent. It is not understandable, why these two defaults differ.

Also add documentation (including example) for each formatter at https://help.jabref.org

List

(this list is work in progress)

• title and booktitle: Ordinals to LaTeX superscript

[koppor]

Related: All tasks described at the top of #60. Although the issue is closed, these tasks still remain.

[koppor]

With JabRef#2051 this should be solved, even I am unsure whether the tasks of #60 are all done.