Add Global Keyboard Shortcuts

Not all of these have been fully implemented yet.

**Jump To**
* `g` then `h` - Home (Latest)
* `g` then `l` - Latest
* `g` then `n` - New
* `g` then `u` - Unread
* `g` then `f` - Favorited
* `g` then `c` - Categories List

**Navigation**
* `u` - Back to topic list
* `k` / `j` - Newer/Older conversation or post
* `o` or `Enter` - Open selected conversation
* <code>`</code> - Go to next section
* `~` - Go to previous section

**Application**
* `c` - Create a new topic
* `n` - Open notifications menu
* `/` - Search
* `?` - Open keyboard shortcut help

**Actions**
* `f` - Favorite topic
* `s` - Share topic
* `<Shift>` + `s` - Share selected post
* `r` - Reply to topic
* `<Shift>` + `r` - Reply to selected post
* `l` - Like selected post
* `!` - Flag selected post
* `b` - Bookmark selected post
* `e` - Edit selected post
* `d` - Delete selected post
* `m` then `m` - Mark topic as muted
* `m` then `r` - Mark topic as regular
* `m` then `t` - Mark topic as tracking
* `m` then `w` - Mark topic as watching
Update french locales
BUGFIX: clicking on the Logo generates a javascript error
Merge pull request #1790 from Bahanix/master

Update french locales
fixed a couple typos in the French translations :fr:
BUGFIX: hide sensitive site settings
Make SMTP authentication mechanism configurable.
there is no need for that much $
Merge pull request #1791 from vikhyat/smtp-auth-option

Make SMTP authentication mechanism configurable.
Merge pull request #1457 from skisulli/keyboard-shortcuts

Global Gmail style keyboard shortcuts
fix jshint
FIX: Email preview with no date caused a server error
When signing up with 3rd party verified email, don't allow changing email in the signup form. Add ability to cancel signup form, which clears its state.
FEATURE: add go to /top page keyboard shortcut
BUGFIX: pressing '?' will now always open the keyboard shortcut modal
Give a better error message from the server if you've been replying too much.
remove debugger
Category description placeholder text mentions that the category won't appear on categories page unless it has topics or the placeholder text is replaced with a real category description.
Remove database.yml from vagrant chef cookbook. Don't need to copy database.yml anymore.
fix typos in EN translations