Modify the source directory structure

Move all source files into a 'Src' directory, and move header files into
an 'Include' directory. Inside each of these sort files by their concern
(networking code in 'Network', OpenGL code in 'Gl', etc.) Update build
systems accordingly; however _remove_ systems that reference Solaris.

The project already prefixed files with character codes indicating their
use but when merging projects it would be favourable to have a more
focused list when looking at certain areas of the codebase.

All Visual Studio projects still attempt the compilation process
correctly. The makefiles designed for Linux have been modified but are
__untested__ due to inaccessiblity. Support for Solaris has been dropped
because of its Oracle association but source code for the platform
remains because it references the X Server.