fix(Options): values using delimiters no longer parse additional valu…

…es after a trailing space

Imagine two args, an option `-o` which accepts mutliple values, and a positional arg `<file>`.
Prior to this change the following (incorrect) parses would have happened:

```
$ prog -o 1,2 some.txt
o = 1, 2, file
file =
```

Only when delimters are used, spaces stop parsing values for the option. The follow are now correct

```
$ prog -o 1,2 some.txt
o = 1, 2
file = some.txt

$ prog some.txt -o 1 2
o = 1, 2
file = some.txt
```

This still has the bi-product of:

```
$ prog -o 1 2 some.txt
o = 1, 2, some.txt
file =
```

This is simply a CLI design and documentation issue (i.e. don't allow options with unlimited
multiple values with positionaln args, or clearly document that positional args go first). This
will also be helped by the upcoming `Arg::require_delimiter`

Relates to #546

src/app/parser.rs

@@ -1255,6 +1255,10 @@ impl<'a, 'b> Parser<'a, 'b>
                     for v in val.split(delim as u32 as u8) {
                         ret = try!(self.add_single_val_to_arg(arg, v, matcher));
                     }
+                    // If there was a delimiter used, we're not looking for more values
+                    if val.contains_byte(delim as u32 as u8) {
+                        ret = None;
+                    }
                 }
             } else {
                 ret = try!(self.add_single_val_to_arg(arg, val, matcher));