* cmake/FindFreeImage.cmake,
	* CMakeLists.txt: Check the availability of sub-libraries in the main
          Makefile.

	* apps/imview/CMakeLists.txt,
	* apps/saliency/CMakeLists.txt,
	* apps/simplification/CMakeLists.txt,
	* apps/supervised-gui/CMakeLists.txt: Conditional compilation if
        QT4 is available.

	* apps/maxtree_comparison/CMakeLists.txt,
	* apps/clattice/CMakeLists.txt,
	* apps/tests/attributes/CMakeLists.txt,
	* apps/tests/tos/CMakeLists.txt,
	* apps/tosgui/CMakeLists.txt,
	* bench/CMakeLists.txt,
	* cli/CMakeLists.txt,
	* tests/io/CMakeLists.txt,
	* tests/morpho/CMakeLists.txt,
	* tests/morpho/component_tree/CMakeLists.txt: Remove hard-coding
        of FreeImage linking and use ${FreeImage_LIBRARIES} instead.