libdeng2|MemoryLogSink: Configurable minimum log entry level
libgui|GLTexture|Image: Use the BGR(A) format when uploading

Todo: Is this part of an OpenGL standard? If not, one can always
do a red/blue swap (e.g., QImage::rgbSwapped()) before uploading
if the extension is not present.
libgui|Font: Rich format colors are acquired from an external object

Any object that implements RichFormat::IStyle can determine which
colors to use for the format.
Client|Widgets|Default Style: Color palette for LogWidget