TimePeriod month behavior patch (time.js)

```
What steps will reproduce the problem?
new TimePeriod(Date.parse('2011-08-25'), Date.parse('2011-09-25'))

What is the expected output? What do you see instead?
expected: months === undefined, days === 0. observed: months === undefined days
=== 31

What version of the product are you using? On what operating system?
latest from svn. macos, chrome 14.0

Please provide any additional information below.

This should fix it unless I'm misunderstanding something.

245c245
< while (d1 < d2 &&
d1.clone().addDays(Date.getDaysInMonth(d1.getYear(), d1.getMonth()) ) < d2) {

---
> while (d1 < d2 && d1.clone().addMonths(1) <= d2) {
251c251
< while (d1 > d2 && d1.clone().addDays(-d1.getDaysInMonth()) > d2) {

---
> while (d1 > d2 && d1.clone().addMonths(-1) >= d2) {
255a256
>

```

Original issue reported on code.google.com by `ehb...@gmail.com` on 7 Oct 2011 at 8:08