Parse date with the option format first

[brenard]

Hello,

If my pull request on mootools-more git is accepted (brenard/mootools-more@9bd7841), this change permit parsing date with the format options before testing other format. In particular case, it avoid parsing error. What do you think ?

Thanks,

[yorickpeterse]

+1 for this, currently struggling trying to get Date.parse() to accept multiple formats that aren't manually set and this commit would fix my problem (or at least make it a lot easier to deal with).