128x128 Icons: Oxygen Icon Theme, exactly as-is

Replaces all icons that have exact drop-in replacements from the Oxygen
Icon Theme, rendered now at 128x128.
128x128 Icons: Oxygen Icon Theme, with adjustments

Replaces all icons that have approximate replacements from the Oxygen
Icon Theme, rendered now at 128x128. Changes in this set adjust the
original theme by brightening icons, grayscaling, or adding gaps in the
canvas area.
128x128 Icons: Anki Logos

Replaces the Anki logo icons (except for anki-logo-thin.png, which is
not really an icon), rendering them at 128x128 from the source SVGs.
128x128 Icons: Crystal Clear, exactly as-is

Replaces all icons that have exact drop-in replacements from the Crystal
Clear set, rendered now at 128x128.
Browser Toolbar: Set icon size to 16x16

Adjusts the markup injected into the HTML view here to use 16x16 icons.
Utility Tooltips: Use button icon in CustomLabel

Adjusts the CustomLabel class used by the tooltip() function so that it
creates a native push button with an icon set on it so that Qt can scale
down the large icon image to 32x32 and not have it look gritty.
128x128 Icons: Rough approximations using Oxygen

Swaps out additional icons that roughly approximate the originals using
the Oxygen SVGs. These are not perfect.
128x128 Icons: Rough approximations using CC

Swaps out additional icons that roughly approximate the originals using
the 128x128 renderings from Crystal Clear. These are not perfect either.
Sound Recorder: Scale media icons down

Sets the record icon to 32x32 and the stop button to 24x24.
Reviewer: Scale star icon down for a marked card

This is inside of an HTML view, and looks fine with done with regular
HTML attributes.
Deck Browser: Scale clock and gear icons down

Patches DeckBrowser#_deckRow() and DeckBrowser#_dueImg() to correctly
scale icons down to fit into the HTML region.
Custom Study Tag Dialog: Add missing image note

TagLimit#rebuildTagList() refers to a nonexistent image (Anki_Fact.png)
which does not exist. This possibly intends to refer to anki-tag.png
instead.
128x128 Composite Tag Icons

These combine the mail-tagged icon from Oxygen with icons from Crystal
Clear: action_edit_add and action_button_cancel.