Changes for GNU/Linux. Adaptation to use GTK+-3.0. Basic implementation of AutoTools-based build system. Builds cleanly with GCC and Clang. Changes were made to some of the Visual Studio files which may need fixing up on the Windows end. Built and tested on OpenSUSE 13.1.
Updated to work with GTK+-3 version 3.8 to support Ubuntu 13.10 build.
Fixed up a few filters and made it clear that the type change for the user_data_key::key_type was a workaround for a known bug in Clang 3.3.
Added build instructions document for GNU/Linux systems.