o2.Utilities.phpToMoment do not handle escaped characters

The current [`o2.Utilities.phpToMoment`](https://github.com/Automattic/o2/blob/9a8be6b17fbfe4c4cb55ac88597020d89279057d/js/utils/timestamp.js#L6-L126) method is not able to handle escaped characters like:

```
j \d\e F \d\e Y
```

This will result in the follow output:

```
24 \122403:00 April \24\-03:00 2017
```

And causing issues on https://br.wordpress.org/team/, https://pt.wordpress.org/team/, and possible other languages.

Start in js/utils/timestamp.js at o2.Utilities.phpToMoment and reproduce the issue with the format string `j \d\e F \d\e Y`. Verify that escaped characters are handled as literals rather than being interpreted as date tokens, and that the resulting localized date output is corrected for the affected WordPress team pages.

Written by the indexing model from the issue text.