cmake: add graphviz feature

CMakeLists.txt

@@ -107,14 +107,15 @@ include(CMakeDependentOption)
 option(BUILD_SHARED_LIBS "Build shared library"                   OFF)
 option(BUILD_EXAMPLES    "Build C++ examples"                     ON )
 
-cmake_dependent_option(WITH_GSL			"Enable GSL"        					ON  "GSL_FOUND"			OFF)
-cmake_dependent_option(WITH_SUNDIALS	"Enable sundials solver suite"			ON  "Sundials_FOUND"	OFF)
-cmake_dependent_option(WITH_SHMEM		"Enable shared memory interface"		ON  "VILLASnode_FOUND"	OFF)
-cmake_dependent_option(WITH_RT			"Enable real-time features"				ON  "Linux_FOUND"		OFF)
-cmake_dependent_option(WITH_PYTHON		"Enable Python support"					ON "Python_FOUND"		OFF)
-cmake_dependent_option(WITH_CIM			"Enable support for parsing CIM files"	ON  "CIMpp_FOUND"		OFF)
-cmake_dependent_option(WITH_OPENMP		"Enable OpenMP-based parallelisation"	ON  "OPENMP_FOUND"		OFF)
-cmake_dependent_option(WITH_CUDA		"Enable CUDA-based parallelisation"		ON  "CUDA_FOUND"		OFF)
+cmake_dependent_option(WITH_GSL				"Enable GSL"        										ON  "GSL_FOUND"					OFF)
+cmake_dependent_option(WITH_SUNDIALS	"Enable sundials solver suite"					ON  "Sundials_FOUND"		OFF)
+cmake_dependent_option(WITH_SHMEM			"Enable shared memory interface"				ON  "VILLASnode_FOUND"	OFF)
+cmake_dependent_option(WITH_RT				"Enable real-time features"							ON  "Linux_FOUND"				OFF)
+cmake_dependent_option(WITH_PYTHON		"Enable Python support"									ON "Python_FOUND"				OFF)
+cmake_dependent_option(WITH_CIM				"Enable support for parsing CIM"				ON  "CIMpp_FOUND"				OFF)
+cmake_dependent_option(WITH_OPENMP		"Enable OpenMP-based parallelisation"		ON  "OPENMP_FOUND"			OFF)
+cmake_dependent_option(WITH_CUDA			"Enable CUDA-based parallelisation"			ON  "CUDA_FOUND"				OFF)
+cmake_dependent_option(WITH_GRAPHVIZ	"Enable Graphviz Graphs"								ON	"GRAPHVIZ_FOUND"		OFF)
 
 if(WITH_CUDA)
     # BEGIN OF WORKAROUND - enable cuda dynamic linking.