Clean up mixins, fix #9100 (no ms-keyframes)

- Spacing tweaks in the general mixins
- Add comments to transform mixins about IE support
- Remove `-ms-keyframes` because only IE10+ supports it, and without
prefix

1 files changed, 1 insertions, 7 deletions

diff --git a/less/progress-bars.less b/less/progress-bars.less
index fe399abf7..ab9832315 100644
--- a/less/progress-bars.less
+++ b/less/progress-bars.less
@@ -18,19 +18,13 @@
   to    { background-position: 0 0; }
 }
 
-// IE9
-@-ms-keyframes progress-bar-stripes {
-  from  { background-position: 40px 0; }
-  to    { background-position: 0 0; }
-}
-
 // Opera
 @-o-keyframes progress-bar-stripes {
   from  { background-position: 0 0; }
   to    { background-position: 40px 0; }
 }
 
-// Spec
+// Spec and IE10+
 @keyframes progress-bar-stripes {
   from  { background-position: 40px 0; }
   to    { background-position: 0 0; }