simplification and cleanup, change p-type

used ptype is normal, with imgcaption as spans..
alignments are similar to alignments of `{{images}}`
added center alignment as block
javascript copies alignment from images to imgcaption, when no alignment was given for the imgcaption
rewritten javascript with jQuery
simplified parse and render functions
added dutch translation
removed getInfo() functions

look at the commits to see the changes, the code reformatting touches almost everything.