Enforce size of MP3 downloads

This adds a check to make sure that downloaded MP3s are at least 1024
bytes long.
Verify output file size of CLI-based services

Adds an additional check in the transcoding step to make sure that the
input file size is at least a number of bytes, additionally adding a
"finally" block so that bad temporary files still get cleaned up.
Fix mistake in instructions under LAME flags

These changes are "NOT" retroactive.
Strip question HTML out of answer HTML

First pass at fixing this -- when pulling out the answer HTML, also pull
out the question HTML and strip it out of the answer HTML.
Strip sounds using native Anki stripSounds

This removes our custom regular expression technique and moves the home
for this to _addon.strip.sounds for all GUI-based classes.
Strip sounds when stripping question from answer

When Anki sends us the answer HTML, and the user has used {{FrontSide}},
any sound tags will be stripped out. With this being the case, we can
use the native Anki stripSounds() to do the same strip to increase the
chances of stripping out the question HTML.
Better window titles

This has the subclasses specify their title explicitly, and the base
modal class takes care of setting the title in the banner and formatting
the regular window title.
Look for #answer HR in answer HTML

Changes the reviewer to search for a <hr id="answer">-type tag and to
strip out anything that leads up to the first such instance -- this
helps avoid repeating the question HTML of the answer card.
Add divider after banner on all windows

This helps create a visual separation between the guts of the window and
the title area.
Add blurb about Back Templates to configuration

Hints to user that s/he can help AwesomeTTS find the fronts of cards on
the answer template with {{FrontSide}} or an #answer divider.
Merge branch 'bug/repeated-question' into develop

Improves the on-the-fly support in AwesomeTTS to not playback the
question / front side of a card when in answer mode if the question /
front side of the card is part of the answer template (e.g. via the
{{FrontSide}} tag).