For arrow functions that are both simple and short, we can avoid using explicit `return` to shorten them even further without hurting readability.
For the `gulp mozcentral` build-target this reduces the overall size of the output by just under 1 kilo-byte (which isn't a lot but still can't hurt).
When the text of an annotation is extracted in using getTextContent, consecutive white spaces
are just replaced by one space and. So this patch add an option to make sure that white
spaces are preserved when appearance is parsed.
For the case where there's no appearance, we can have a fast path to get the correct string
from the Content entry.
When an existing FreeText is edited, space (0x20) are replaced by non-breakable (0xa0) ones
to make to see all of them on screen.
