Feature request: Cover letter integration

Hello Xavier, great package. I've used it to get two different jobs so far and am working on a third (such is life in academia).

In the examples directory, there is a template for a letter, but I am wondering how difficult it would be to add letter writing functionality directly to the moderncv class. In formatting my CV, I've already entered all of my personal information, I've chosen my fonts, my font style, and my colors. Currently, I then have to copy these attributes over to my letter.tex file, and if I make a style change to either file, I have to make sure to propagate it through. I would like to have a \begin{coverletter} environment that would take the personal information from my CV header, start a new page, and then typeset my letter in a manner consistent with my CV (same fonts, color accents, etc.). That way, my CV and cover letter end up in the same PDF for easy emailing and I can have a single unified file for every job I apply for, and I can automatically add such things as the company name to the PDF keywords for easy searching when I get a callback.

Thanks again!