Fix #650: Resetting configuration raises error when file do not exist
Fix #627 Clear text fields when removing a talk or removing all talks
Fix #664 Feedback when desktop record region selected
Skip tests related to RTMP plugin for Windows

The RTMP plugin is not included in GStreamer for Win32, so the test based on it will fail on Windows.
The workaround is to skip the RTMP test on Windows.
Updates to http errors, and validation

Changed HTTPError class to have more standard error messages, and
custom inner descriptions.

Decoupled JSON Schemas from validate module, now schemas are either
generated by config classes, or stored statically in the api blueprint.

Added JSON validation schemas to recording api Blueprint

Updated validation tests for validate.py changes, changed xunit setups
to pytest fixtures
Fixes #576 High/Low DPI Adapting

The Qt UI would change the size according to the logical DPI of the computer.
Only Windows and Linux have been tested. (Should also work on Mac but have not tested).
The unit test for the new file is also added.
:memo: Improve docstrings

Make them more readable and informative.
Also fix punctuation, spelling, and grammar mistakes.

Related to #640
Fix #623 Add audio/video quality configuration support
Fix PEP8 coding style violations in Sphinx config

Fix minor PEP8 violations in docs/source/conf.py.

As part of http://24pullrequests.com
Refactor rss related tests and resources for testing

Related #671
Related #484
Fix #675 Update csv import plugin to support presentation fields
Add outline of new database schema and TODO list to implement it

Related #667
Related #484
Related #671
Update YouTube docs

[skip ci]