Explicitly set monospace font on input.raw_input

Also do not explicitly set monospace font in raw_container_input,
because that the container's width to be inconsistent with the (later)
output div's width.

notebook/static/notebook/less/outputarea.less

@@ -157,7 +157,6 @@ div.output_javascript:empty {
 /* raw_input styles */
 
 div.raw_input_container {
-    font-family: @font-family-monospace;
     line-height: @code_line_height;
     // for some reason, em padding doesn't compute the same for raw_input
     // that is not the first input, but px does
@@ -169,7 +168,7 @@ pre.raw_input_prompt {
 }
 
 input.raw_input {
-    font-family: inherit;
+    font-family: @font-family-monospace;
     font-size: inherit;
     color: inherit;
     width: auto;