Add rm utility and improve further

rm.nim

@@ -0,0 +1,16 @@
+import cligen, os
+import common
+
+proc main(files:seq[string], force=false, recursive=false) =
+    for file in files:
+        if existsFile(file):
+            removeFile(file)
+        elif existsDir(file):
+            if recursive:
+                removeDir(file)
+            else:
+                echo "rm: cannot remove '" & file & "': Is a directory"
+        else:
+            echo "rm: cannot remove '" & file & "': No such file or directory"
+
+dispatch(main, version=("version", nimbaseVersion))