postHoverInfo shows formatted title

This addresses "link to /r/subreddit referenced in the title for xposts, etc.".  It's a bit of a sledgehammer approach, though,
postHoverInfo gets its own SnuOwnd parser if it can't borrow commentPreview's
showImages stashes link's original href
for future use in case it's changed by a site module
popupHoverInfo shows post's link (original if changed)
also option to open links in a new tab
keep "get bits of the popup function" together
popupHoverInfo has 3s delay because 800ms is too dang soon
popupHoverInfo header includes settings button
postHoverInfo internal refactoring
Split out "make elements", "get data from thing", "get thing"
RESUtils.subredditRegex for extracting subreddit name from reddit url
postHoverInfo getSubreddit for extracting subreddit name from thing
.RESDialogSmall .buttons styling
popupHoverInfo buttons list
popupHoverInfo buttons: "related" and "xposts" (duplicates)
popupHoverInfo "image xposts" button for reposts of direct image link
although this maybe isn't immediately obvious.. maybe I should add tooltips
popupHoverInfo's makeLink supports tooltips
popupHoverInfo "image xpost" button tooltip