refactor(sass): change order of Sass imports to use global vars

This allows us to use the variables in ionic.theme.default without
having to import it. This new order is consistent with how the mode
specific globals already work.

core/src/components/content/content.scss

@@ -1,4 +1,4 @@
-@import "../../themes/ionic.theme.default";
+@import "../../themes/ionic.globals";
 
 // Content
 // --------------------------------------------------

core/src/components/item-sliding/item-sliding.scss

@@ -1,4 +1,4 @@
-@import "../../themes/ionic.theme.default";
+@import "../../themes/ionic.globals";
 
 // Item Sliding
 // --------------------------------------------------

core/src/components/list/list.scss

@@ -1,5 +1,4 @@
 @import "../../themes/ionic.globals";
-@import "../../themes/ionic.theme.default";
 
 
 // List

core/src/themes/ionic.globals.scss

@@ -11,6 +11,8 @@
 // Global Mixins
 @import "./ionic.mixins";
 
+// Default Theme
+@import "./ionic.theme.default";
 
 // Global app direction
 $app-direction: ltr !default;

core/src/themes/ionic.theme.default.ios.scss

@@ -1,5 +1,3 @@
-@import "./ionic.theme.default";
-
 
 // iOS General Colors
 // --------------------------------------------------

core/src/themes/ionic.theme.default.md.scss

@@ -1,12 +1,7 @@
-@import "./ionic.theme.default";
 
 // Material Design Default Theme
 // ----------------------------------
 
-// Material Design General
-// --------------------------------------------------
-
-
 // Material Design General Colors
 // --------------------------------------------------
 $backdrop-md-color:                         $backdrop-color !default;

core/src/themes/ionic.theme.default.scss

@@ -1,5 +1,3 @@
-@import "./ionic.globals";
-
 // Default Foreground and Background Colors values
 // Allows users to override an foreground / background colors
 // TODO: @color-mod: remove all this