Dutch translation improvements

DO NOT MERGE YET! STILL WIP!

I'm looking at the Dutch translations and see if I can fix or/and improve some translations. I will look further today at this, so till I say it, do not merge it yet. In the mean time the other Dutch translators (for example @Gymnasiast ) can look at the changes I have made so far and can descide if it's a good change or not. Just want to let you know I'm working on it, so we don't do dubble work :) 
Oh, en nu we toch bezig zijn, STR_3428 kan beter zo geformuleerd worden, denk ik:
STR_3428 :{SMALLFONT}{BLACK}De bochten een banking geven (schuinleggen) zal de rit prettiger maken, aangezien de passagiers in hun stoelen geduwd zullen worden in plaats van naar de zijkanten...