[GNU Classpath] Port the GTK+ AWT support for GTK+ 3

by Farshad Muhammad for GNU Project

GTK (GIMP Toolkit) is an open source toolkit for Linux and Unix systems for GUI production and is used by many java applications. The GNU Classpath at the moment ships with a GTK+2 peer which provides most of its GUI support, which is unfortunately outdated as most GNU/Linux distributions are packaged and shipped with GTK+3. Thus this project aims to prepare and port the GTK+ peer to work and build with GTK+ 3 providing and ideally allowing for the uses of the new GTK+3 features with GNU Classpath. The porting process will be conducted following a guide provided by GTK+. The porting process should also be done in such a manner as to make the classpath backwards compatible with GTK+ 2, this is to avoid future problems, if any occur with the usage of GTK+ 3.