clarity: change flag "Notify" to "Private message"
Clean up site_settings.yml

 - Hide several variables that the client does not use
 - Use concise default syntax when possible
Shuffle around the order of site settings

The goal of this is twofold:
 - Make the more commonly changed settings higher
 - Find groups for more uncategorized settings

Additionally, the SEO category was deleted, its contents folded into Security and Spam.
make setting descriptions less big/dark
make user setting desc less big/dark
add additional reply via email help text example
clarify this is an incoming-only email
make header only box-shadow on bottom
tighten up problem messages display
Update client.zh_CN.yml

I have to say it's not a pleasure experience to update locale file. It seems Transifex doesn't sync  properly.
Merge pull request #2164 from fantasticfears/patch-1

Update client.zh_CN.yml
BUGFIX: bound avatars in revision history UI
a few simple style clean-ups
Merge pull request #2165 from awesomerobot/master

a few simple style clean-ups
embedded iframe css improvements
Merge pull request #2156 from riking/fix-necro

Only warn about necromancy when replying
5px not 5
add img max width to embedded iframe comments
add Other Optional Stuff section, link swap guide
omit needless words