Rich text editor tweaks and updates

We've made some minor tweaks to the writing experience in rich text elements:

• Consecutive spaces: From now on, you won't able to add two consecutive spaces in a row, unless you specify that space as a non-breaking space ( ) by hitting SHIFT+SPACE.
• Empty paragraphs: In the past, when you created empty paragraphs they'd be removed when clicking out of the rich text editor. From now on, those empty paragraphs will stay put, unless you delete them.

...and a couple bug fixes:

• Links to nested pages: In the past, links to pages within folders would sometimes not include that folder within the URL structure. So we fixed that.
• Select and replace: You might have run into issues with the cursor jumping around while selecting text and typing to replace it, so we fixed that.