new rounded corners mixin makes rounded corners easy (for browsers that support them) and allows rounding all corners, corners on one side, or single corners.

changed rounded corners mixin to border radius mixin, and changed the functions to match the border-radius CSS3 standard

frameworks/compass/stylesheets/compass/utilities/general/_border_radius.sass

@@ -0,0 +1,47 @@
+!default_border_radius ||= 5px
+
+// Round all borders by amount
+=border-radius(!radius = !default_border_radius)
+  border-radius= !radius
+  -moz-border-radius= !radius
+  -webkit-border-radius= !radius
+
+// Round radius at position by amount.
+// values for !vert: "top", "bottom"
+// values for !horz: "left", "right
+=border-corner-radius(!vert, !horz, !radius = !default_border_radius)
+  border-#{!vert}-#{!horz}-radius= !radius
+  -moz-border-radius-#{!vert}#{!horz}= !radius
+  -webkit-border-#{!vert}-#{!horz}-radius= !radius
+  
+=border-top-left-radius(!radius = !default_border_radius)
+  +border-corner-radius("top", "left", !radius)
+
+=border-top-right-radius(!radius = !default_border_radius)
+  +border-corner-radius("top", "right", !radius)
+
+=border-bottom-left-radius(!radius = !default_border_radius)
+  +border-corner-radius("bottom", "left", !radius)
+
+=border-bottom-right-radius(!radius = !default_border_radius)
+  +border-corner-radius("bottom", "right", !radius)
+
+// Round top corners by amount
+=border-top-radius(!radius = !default_border_radius)
+  +border-top-left-radius(!radius)
+  +border-top-right-radius(!radius)
+
+// Round right corners by amount
+=border-right-radius(!radius = !default_border_radius)
+  +border-top-right-radius(!radius)
+  +border-bottom-right-radius(!radius)
+
+// Round bottom corners by amount
+=border-bottom-radius(!radius = !default_border_radius)
+  +border-bottom-left-radius(!radius)
+  +border-bottom-right-radius(!radius)
+
+// Round left corners by amount
+=border-left-radius(!radius = !default_border_radius)
+  +border-top-left-radius(!radius)
+  +border-bottom-left-radius(!radius)