More import removals

Following the series of commits removing deprecated features in
Django 1.7, here are some more unneeded imports removed and other
minor cleanups.
Removed comment from setup.cfg which broke newer wheel versions.
Removed django.contrib.auth.views.password_reset_confirm_uidb36() view to finish its accelerated deprecation schedule.
Fixed #20660 -- Do not try to delete an unset FieldFile

Thanks stanislas.guerra at gmail.com for the report and
Baptiste Mispelon for the review.
Do not allow FileSystemStorage.delete to receive an empty name

Refs #20660.
Fixed #18592 -- Prevented crash when accessing MySQL _last_executed

Thanks reames at asymmetricventures.com for the report.
Removed compatibility code for streaming responses.

This code provided a deprecation path for old-style streaming responses.

Refs #6527, #7581.
Advanced deprecation warnings for Django 1.7.
Simplified description of HttpResponse(<iterator>)

Related to 8b9b8d3b.
Fixed #20677 - Typos in generic_inlineformset_factory docs.

Thanks Riley Strong for the report.
Merge pull request #1316 from ramiro/int_pk_pwd_reset
Report wrongly-typed settings and abort, as originally planned.

Thanks Claude for the heads up. Refs #12493 and commit 5e08b792.
Define the SessionStore inside __init__ instead of process_request

It's unnecessary to run this on every request, since technically, settings *should be* immutable.
Stopped calling loaddata with commit=False.

This was a stealth option only used by the tests, and it isn't useful
any more since `atomic` provides nested transactions.
Introduced getters for connection.autocommit and .needs_rollback.

They ensure that the attributes aren't accessed in conditions where they
don't contain a valid value.

Fixed #20666.
Removed a comment that wasn't adding a value.

In the intervening years, RelatedField has become less of a hack (though it still is one). Anyone who wants to can re-instate the comment, but please add more details.
Updated FAQ on Python versions to explain 2 vs 3.

Required the latest version for each Python series to minimize
bookkeeping in the future.

Forward-port of c1d8f3b from stable/1.6.x.
Stopped branding Python 3 support as experimental.

Forward-port of 0de21a6 from stable/1.6.x.
Bumped minimum Python version requirement to 2.7 in Django 1.7.
Removed some conditional code only needed under Python 2.6.