Wrap longitude values explicitly

Leaflet 0.5 no longer wraps longitude values, so we need to do it.
Put some white space back to make things readable
Compute size of rich text preview pane correctly
Remove redundant CSS rule - table headings are already bold
Fix lists in rich text to display properly

Add a "richtext" class to anything which contains text rendered
by our rich text library, and move styles which were only being
applied to diary entries to apply to all rich text.
Merge remote-tracking branch 'origin/master' into owl-history-tab