better docs + minor cleanup...

Signed-off-by: Alex A. Naanou <alex.nanou@gmail.com>

ADVANCED.md

@@ -28,6 +28,7 @@ For basics see [README.md](./README.md)
 			- [Disabling or redefining a built-in option](#disabling-or-redefining-a-built-in-option)
 			- [`-` / `--`](#-----)
 			- [`-*` / `@*`](#---)
+				- [`<parser>.delegateUnknownToParent`](#parserdelegateunknowntoparent)
 			- [`-v` / `--version`](#-v----version)
 			- [`-q` / `--quiet`](#-q----quiet)
 			- [`-h` / `--help`](#-h----help)
@@ -383,11 +384,22 @@ for example.
 
 Handle options/commands for which no definition is found.
 
-By default `-*` will print an "unhandled option/command" error and terminate.
+By default `-*` will:  
+- on root parser: print an "unhandled option/command" error and terminate.
+- on nested parser: delegate the option to the parent.
 
 By default `@*` is an alias to `-*`.
 
 
+##### `<parser>.delegateUnknownToParent`
+
+Controls the default behavior of a nested parser when encountering an unknown option.
+
+If `true` (default) the option will be delegated to the parent parser. If `false` 
+behave the same way as the root parser, i.e. printing an error.
+
+
+
 #### `-v` / `--version`
 
 This will output the value of `.version` and exit.

argv.js

@@ -1082,8 +1082,8 @@ object.Constructor('Parser', {
 		//section_doc: ...,
 		handler: function(_, key, value){
 			// delegate to parent...
-			if(this.delegateUnknownToParent 
+			if(this.parent
-					&& this.parent){
+					&& this.delegateUnknownToParent){
 				this.parent.rest.unshift(
 					value === undefined ?
 						key

package.json

@@ -1,6 +1,6 @@
 {
   "name": "ig-argv",
-  "version": "2.17.0",
+  "version": "2.17.1",
   "description": "simple argv parser",
   "main": "argv.js",
   "scripts": {