Drop support for -webkit-calc

Changes browser support to Chrome >= 26 and Safari >= 7.
All -webkit-calc usages have been updated to lose the prefix.

Officially a breaking change, but realistically changes nothing for our customers and requires no changes from consumers.

Remove link-callout styles

• remove link-callout styles

Added nav-toolbar--compact modifier

Added nav-toolbar--compact modifier
On large screens this sets padding-top to 0 in actionbar, on all other screens it remains the same

Removes gauges cookies

In order for the website to be compliant with cookies new legislation we removed unused cookies

Expand button toolbar for XL screen sizes

A fix for button toolbar buttons expanding for XL screen sizes

Changing the styles of the navigation

This PR removes the little pound graph we had in the background.

Update callout margins

Before: Callout > was 10px away from link and moved 10px when hovered

After: Now it's 8px away and will move 4px

Callouts and fast-flag

Adds 3 new classes:
.link-callout which renders an emphasized link
.callout-container which allows you to interact with the callout in a larger container
.fast-flag which is the same as the old .flag

Make dropdowns also animate when fading away

Merge pull request #197 from transferwise/dropdown-animation-enhancement

Make dropdowns also animate when fading away.

Fix hover state for active dropdown menuitems

The disabled buttons styling caused a greater specificity, overriding hover states.
Active style should not change when hovering over the element.