libgui|Image: Added fromData() method, support for loading PCX images
libgui|Debug: Print source file/line when a GL error occurs
Refactor|libappfw: Const'd a method of BaseWindow
libgui|GLState: Querying a normalized viewport rectangle
Renderer|FX: Added a bloom post-processing effect

fx::Bloom takes the frame buffer contents and applies a bloom filter
on them. Bloom is enabled by default.

Settings for Bloom were added to the Renderer Appearance sidebar.
UI|Client: Renderer Appearance sidebar remembers which groups are open

Uses the widget state persistency mechanism.
Renderer|FX: Bloom tweaks

Only render bloom when a map is loaded. Also, raised the bloom
threshold a little bit.
Fixed|libappfw: Crash after closing popup (double delete)

If a popup was auto-deleted at popup dismissal, but the parent was
deleted before garbage recycling, the widget was deleted twice.
Renderer|FX: Added bloom to appearance profiles

Also added a extra cvar "rend-bloom-complexity" that controls whether
the effect is 1-pass or 2-pass (default: 2-pass).
Fixed|Client: Ignore unknown settings in profile when reading
Debug|Unix|libdeng2: Added a backtrace print macro

Perhaps the Best Thing Ever for non-invasive debugging.
Fixed|UI|Client: Group visibility in the Games dialog

The state of the groups were restored from persistent state, which
might show groups that are supposed to be filtered out.
UI|Client: Tweaks

Reordered/reworded the 'help' command's output a little.
Fixed|libappfw: Failed assert when deiniting widget not part of tree

Widgets should remember which atlas they have been using and not
ask the root widget, which may not be available any more.
Renderer|FX: Moved color filter later in the FX stack

If color filter is applied before bloom, it can alter the resulting hue
and brightness of the filter quite much.

Also, as the color filter is used for pain/etc. effects (visualization
for things that the player senses) they should be applied after the
optical effects.
libgui|GLTarget: If validation fails, do a full reset of the instance
Fixed|libgui: Vertex builder position accuracy issue in makeRing

Make sure the ring starts and ends at the exact same position.
Fixed|Doom|Doom64: Incorrect cvar value range for 'player-color'
Client: Don't warn about failed auto-selection of game
Fixed|Heretic: Removed invalid cvar 'player-weapon-order8'

Heretic only has eight weapons (0...7).