Frontend for accounts.new_post_in_river setting.
WIP: Post a new post from river views.
Load freshly-posted post in-river.
When showing "n new posts", don't count posts which are already shown in the river.
Sort if/else by block size ascending.
Clear New Post textarea on successful post.
Clear New Post notice message on keypress in New Post textarea.
Actually save new_post_in_river account setting.  Use this setting to conditionally display the New Post form.
Make CSS selector more specific: This fixes a style bug on the Visibility selector in the New Post form in river view.
Style fixes for New Post in river page.
JS for posting from river should not be triggered in regular New Post page.
Refactor to remove hanging semicolons.
Slide message down instead of merely show()ing it.
Moar hanging semicolon cleanup.
Don't use fixed width for form#post-new in river view.
Revert "Moar hanging semicolon cleanup."

This reverts commit bcf16f2ebc2b3f4cacfb7cb468722b75cb083965.
DRY up common view code for posting a new post.
Merge branch 'new-post-in-river'