[css-multicol-2] column-height and column-wrap

Defines that column-height creates a multicol container  #11975

Also defines column-wrap: auto #11754

Author: rachelandrew

css-multicol-2/Overview.bs

@@ -202,7 +202,7 @@ In addition, once final, it will replace and supersede the following:
 <h2 id="the-multi-column-model">
 The multi-column model</h2>
 
-	An element whose 'column-width' or 'column-count' property is not ''column-width/auto''
+	An element whose 'column-width', 'column-count', or 'column-height' property is not ''column-width/auto''
 	establishes a <dfn lt="multi-column container|multicol container" oldids="multi-column-element" export>multi-column container</dfn>
 	(or <i>multicol container</i> for short),
 	and therefore acts as a container for [=multi-column layout=].
@@ -871,8 +871,8 @@ The number and width of columns</h2>
 
 	<pre class=propdef>
 	Name: column-wrap
-	Value: nowrap | wrap
-	Initial: nowrap
+	Value: auto | nowrap | wrap
+	Initial: auto
 	Applies to: multicol containers
 	Inherited: no
 	Percentages: n/a
@@ -882,10 +882,14 @@ The number and width of columns</h2>
 	</pre>
 
 	The column-wrap property controls the behavior of overflow columns in continuous media.
-	The property only takes effect if 'column-height' is not 'auto',
-	and there is more content than will fit in a single row of columns at the specified 'column-height'.
+	Overflow columns occur when there is more content than will fit in a single row of columns at the specified 'column-height',
+	or inside a height defined by the multicol container.
 
 	<dl dfn-type=value dfn-for=column-wrap>
+		<dt><dfn>auto</dfn>
+		<dd>
+			If 'column-height' is not 'auto' behaves as the value 'wrap' otherwise acts as 'nowrap'.
+		
 		<dt><dfn>nowrap</dfn>
 		<dd>
 			Overflow columns are created in the inline direction.
@@ -932,7 +936,7 @@ The number and width of columns</h2>
 	New rows repeat until all content is displayed.
 	</div>
 
-	Issue(11754): The addition of this property is as yet unresolved.
+	Issue(11754): The issue relating to the addition of this property is still open due to debate as to whether it's required.
 
 	Issue(11754): What happens if you set a height on the multicol container, 'column-wrap: wrap' but no 'column-height'?
 	Options are 1: The 'column-wrap' property is ignored. 2: 'column-height: auto' resolves to the available space