Update dutch.txt, also fixes #287 for Dutch

Also contains a few additional strings and fixes typos.
Added new OpenRCT2 strings for language switching
Extra translated strings, some fixed typos
Trying to solve gfx issues
Fixed Zoom bug. No longer uses undefined behaviour.
Merge pull request #298 from duncanspumpkin/gfx_play

Gfx play
Merge branch 'master' of https://github.com/Gymnasiast/OpenRCT2 into Gymnasiast-master

Conflicts:
	data/language/dutch.txt
Merge branch 'Gymnasiast-master'
Merge branch 'master' of https://github.com/IntelOrca/OpenRCT2

Conflicts:
	data/language/dutch.txt
add research window

As seen from RollerCoaster Tycoon 1. This allows the player to change the priorities in a "no money" park. I find it also more logical than the two research panels being separated in finances and new ride windows.
New string and some fixes

Also followed recommendations in #296
Fixed one string
Merge pull request #299 from Gymnasiast/master

Another update for dutch.txt