Add Qt4 source build functionality to mira-client SCons

The current mira-client SCons build system (which consists of the top-level /mira-client/SConstruct script and the /mira-client/src/SConscript script) is incapable of building the Qt resources file (/resources/Resources.qrc) and the Qt header files (/mira-client/include/gui/qt/*.h) automatically.

This blueprint outlines how we can go about automating this process. The SCons Qt4 tool created by David Garcia Garzón and released under a BSD license is available here: http://iua-share.upf.edu/svn/clam/trunk/CLAM/scons/sconstools/qt4.py We can implement this tool into the mira-client SCons system to locate the Qt resources and header files for us, build them and include the resulting files in the build process.