cmdopt2: rename arg as args

CMakeLists.txt

@@ -286,8 +286,8 @@ list (
     cmdopt.cpp
     cmdopt.hpp
     cmdopt2/fwd.hpp
-    cmdopt2/arg.cpp
-    cmdopt2/arg.hpp
+    cmdopt2/args.cpp
+    cmdopt2/args.hpp
     cmdopt2/parser.cpp
     cmdopt2/parser.hpp
     colour.cpp

cmdopt2/args.cpp

@@ -1,4 +1,4 @@
-#include "./arg.hpp"
+#include "./args.hpp"
 
 using cruft::cmdopt2::positional;
 using cruft::cmdopt2::keyword;

cmdopt2/parser.cpp

@@ -1,6 +1,6 @@
 #include "./parser.hpp"
 
-#include "./arg.hpp"
+#include "./args.hpp"
 
 using cruft::cmdopt2::parser;
 

test/cmdopt2.cpp

@@ -1,6 +1,6 @@
 #include <cruft/util/tap.hpp>
 #include <cruft/util/cmdopt2/parser.hpp>
-#include <cruft/util/cmdopt2/arg.hpp>
+#include <cruft/util/cmdopt2/args.hpp>
 
 #include <iostream>