Add a margin for frameless images

Might as well just reuse the thumb stuff, I guess.

Bug: T196356
Change-Id: Ic0497b2003bea9a5c739fd47858be545b16f2812

resources/screen-common.less

@@ -521,12 +521,14 @@ ul {
 
 /* Thumbnails */
 /* @noflip */
+.floatright,
 .tright {
 	margin: 0 0 0.5em 0.5em;
 	padding: 0 0 1em 1.5em;
 }
 
 /* @noflip */
+.floatleft,
 .tleft {
 	margin: 0 0.5em 0.5em 0;
 	padding: 0 1.5em 1em 0;

resources/screen-mobile.less

@@ -251,11 +251,13 @@ div.thumb {
 	margin: 1em auto;
 }
 
+.floatright,
 .tright {
 	margin-left: 0;
 	padding-left: 0;
 }
 
+.floatleft,
 .tleft {
 	margin-right: 0;
 	padding-right: 0;