translation GnuCash v. 1.7.7 nl

[HJ Heins]

> 
> Just a quick note: In future po files, can you please remember to set the 
> "PO-Revision-Date" to the date of your last editing? This is an important 
> date for other maintainers to judge whether this translation is more 
> up-to-date than another. I've set this now by myself.
> 
Oww... forgot!

I'm sorry, I will put it in there the next time :-)

Hendrik-Jan Heins