Agar-DEV: Developer tools for Agar

The Agar-DEV library is normally only included in debug builds and used from applications compiled in debug mode. It implements a number of tools useful to developpers, such as a "GUI debugger", useful to display changing widget variables, when implementing new widgets.

Agar-DEV is bundled with the Agar distribution, but compiled as a separate library. Applications should link against `agar-dev-config --libs` (or the ag_dev.dll library on Windows).

See AG_Intro for the Agar-DEV API reference.