Implement new argument parsing using getopt and add the corresponding library to externals

externals/getopt/CMakeLists.txt

@@ -0,0 +1,11 @@
+set(SRCS
+            getopt.c
+            )
+set(HEADERS
+            getopt.h
+            )
+
+create_directory_groups(${SRCS} ${HEADERS})
+add_library(getopt ${SRCS} ${HEADERS})
+target_compile_definitions(getopt INTERFACE STATIC_GETOPT)
+target_include_directories(getopt INTERFACE ${CMAKE_CURRENT_SOURCE_DIR})