_tooltip.scss: replaced hard-coded 85% with `$tooltip-max-width`

tooltip show become too wide on large screens, since their `max-width:
85%` refers to the whole width of the screen. I have added a parameter
`$tooltip-max-width` and chose a default of `300px`.
Add toggled event, fire callback on toggled

Added a toggled event to match Tabs (fires after toggle completes).

Added callback being fired when active item is clicked (previously only
non-active items being clicked fired the callback).
Anchor destination thresold

The destination thresold parameter should be taken in consideration when we click on an anchor link.
split $tabbar-height into $tabbar-height and $tabbar-icon-width

by splitting tab bar height in height and icon-width (respectively for height and width settings related to the tab bar and tab bar sections), you can have wider icons/clickable areas in the tab bar, controllable via _settings.
$tabbar-icon-width defaults to $tabbar-height for a square icon

Signed-off-by: Maarten Ottens <m@maartenottens.com>

Conflicts:
	scss/foundation/components/_offcanvas.scss
Whoops overlooked mixin parameter while cherry-picking
Fix the centered column floating glitch by targeting specific selector, instead of using !important.

Should fix both #4200 and #4624.
Moving CSS rules that are irrelevant to $size out of the mixin grid-html-classes($size).
Adding size-specific centered & uncentered styles into @grid-html-classes mixin.
Avoid introducing new variables
Kitchen sink tweaks

Subheader presentation plus <dt>, <dl> and <dd> fixes.
Kitchen sink tweaks

Better describe dropdown button types
Kitchen sink tweaks

Tighten wording on panels.
Kitchen sink tweaks

Tighten wording on reveal.
Kitchen sink tweaks

Expanded labels on split buttons
Merge pull request #5186 from MrOrz/master

Remove `!important` and reorder certain styles in grid system to fix centered grid
Merge pull request #5190 from karland/patch-2

_tooltip.scss: replaced hard-coded 85% with $tooltip-max-width
Modify _panel.scss to address pull request [#5187](https://github.com/zurb/foundation/commit/e806a94572f7aa220db0ed361d606799f796d4f4)
Merge pull request #5323 from petecooper/master

Kitchen sink doc tweaks - no new functionality
Merge pull request #5279 from johnraz/SplitTabbarHeightAndWidth

Revival for #4086, split tab bar height and tab bar width
Merge pull request #5274 from glafarge/patch-4

Anchor destination thresold