Fix \inlineimage caption handling

The \inlineimage cmd assumes that rest of the text after the image name as caption for the image, so all \inlineimage instances at the moment use a newline after the image, to avoid the text being caption for the image. This behavior deceives the purpose of \inlineimage, which should be inline to the text that follows. The captions to inline image should be wrapped in braces to differentiate between the normal text and captions.