fix(mdButton): fab vertical positioning

Affects the following CSS classes:
md-fab-bottom-right
md-fab-bottom-left
md-fab-top-right
md-fab-top-left

Closes #1031. Closes #1032.

src/components/button/button.scss

@@ -5,7 +5,8 @@ $button-padding: 2px 6px 3px !default;
 $button-fab-width: 56px !default;
 $button-fab-height: 56px !default;
 $button-fab-padding: 16px !default;
-$button-fab-toast-offset: $toast-height + $toast-margin !default;
+
+$button-fab-toast-offset: $button-fab-height * 0.75;
 
 /**
  * Position a FAB button.
@@ -47,9 +48,9 @@ $button-fab-toast-offset: $toast-height + $toast-margin !default;
   cursor: pointer;
   overflow: hidden;   // for ink containment
 
-  transition: box-shadow $swift-ease-in-out-duration $swift-ease-in-out-timing-function,
-              background-color $swift-ease-in-out-duration $swift-ease-in-out-timing-function,
-              transform $swift-ease-in-out-duration $swift-ease-in-out-timing-function;
+  transition: box-shadow $swift-ease-out-duration $swift-ease-out-timing-function,
+              background-color $swift-ease-out-duration $swift-ease-out-timing-function,
+              transform $swift-ease-out-duration $swift-ease-out-timing-function;
 
   &.ng-hide {
     transition: none;
@@ -75,10 +76,10 @@ $button-fab-toast-offset: $toast-height + $toast-margin !default;
 
   &.md-fab {
 
-    @include fab-position(bottom-right, auto, $button-fab-width/2, $button-fab-height/2, auto);
-    @include fab-position(bottom-left, auto, auto, $button-fab-height/2, $button-fab-width/2);
-    @include fab-position(top-right, $button-fab-height/2, $button-fab-width/2, auto, auto);
-    @include fab-position(top-left, $button-fab-height/2, auto, auto, $button-fab-width/2);
+    @include fab-position(bottom-right, auto, ($button-fab-width - $button-fab-padding)/2, ($button-fab-height - $button-fab-padding)/2, auto);
+    @include fab-position(bottom-left, auto, auto, ($button-fab-height - $button-fab-padding)/2, ($button-fab-width - $button-fab-padding)/2);
+    @include fab-position(top-right, ($button-fab-height - $button-fab-padding)/2, ($button-fab-width - $button-fab-padding)/2, auto, auto);
+    @include fab-position(top-left, ($button-fab-height - $button-fab-padding)/2, auto, auto, ($button-fab-width - $button-fab-padding)/2);
 
     z-index: $z-index-fab;