Send post_delete signals immediately

In a normal relational construct, if you're listening for an event
that signals a child was deleted, you dont expect that the parent
was deleted already.

This change ensures that post_delete signals are fired immediately
after objects are deleted in the graph.
Add David Cramer to AUTHORS
Move signal disconnect into finally block
Move logic seperation as its not longer repetitive
Improve test to ensure that post_delete was actually called
Merge pull request #642 from dcramer/patch-1

Send post_delete signals immediately
Fixed #19092 -- Completed Lithuanian date/time formats

Thanks Tadas Dailyda for the report and the patch.
Fixed #19605 - Removed unused url imports from doc examples.

Thanks sergzach for the suggestion.
Clarified WizardView.get_form_prefix doc, refs #19024
Fixed #19614 -- Missing request argument in render call.

Thanks Dima Pravdin for the report.
Removed some uses of the deprecated assertEquals
Fixed a typo in the error reporting docs.
Fixed #19099 -- Split broken link emails out of common middleware.
Removed obsolete comment.

These features are implemented, tracked in tickets, or not necessary.

Thanks Bruno Renié.
Kill mx.TextTools with fire
Merge pull request #649 from mattrobenolt/patch-1

Removed untested optional dependency on mx libraries.
Fixed #19597 - Added some notes on jQuery in admin.

Thanks Daniele Procida.