Fix 2.0 to be backwards compatible with emsize variables from 1.0

src/themes/default/globals/site.variables

@@ -25,13 +25,10 @@
 --------------------*/
 
 /* This is the single variable that controls them all */
-@emValue  : 14;
-
-/* The size of all UI */
-@emSize   : unit(@emValue, px);
+@emSize   : 14px;
 
 /* The size of page text  */
-@fontSize : unit(@emValue, px);
+@fontSize : 14px;
 
 /*-------------------
     Border Radius
@@ -86,18 +83,18 @@
 --------------------*/
 
 /*
-  To have sizing resolve to a specified pixel values adjust
-  the numerator to the desired pixel size
+  This ensures all relative sizes are exact pixels
+  expressed in em
 */
 
-@miniSize        : (10 / @emValue);
-@tinySize        : (12 / @emValue);
-@smallSize       : (13 / @emValue);
-@mediumSize      : (14 / @emValue);
-@largeSize       : (16 / @emValue);
-@bigSize         : (18 / @emValue);
-@hugeSize        : (20 / @emValue);
-@massiveSize     : (24 / @emValue);
+@miniSize        : (10 / unit(@emValue));
+@tinySize        : (12 / unit(@emValue));
+@smallSize       : (13 / unit(@emValue));
+@mediumSize      : (14 / unit(@emValue));
+@largeSize       : (16 / unit(@emValue));
+@bigSize         : (18 / unit(@emValue));
+@hugeSize        : (20 / unit(@emValue));
+@massiveSize     : (24 / unit(@emValue));
 
 
 /*-------------------