[css-align] Make 'auto' only behave as 'normal' when finding the *actual* position of an abspos; revert to looking at *-items when finding the staticpos. Fixes #440.

Author: tabatkins

css-align/Overview.bs

@@ -890,11 +890,14 @@ Inline/Main-Axis Alignment: the 'justify-self' property</h3>
 	the box's outer edges are aligned within its <a>alignment container</a>
 	<a href="#alignment-values">as described by its alignment value</a>.
 
-	The <dfn value for="justify-self">auto</dfn> keyword is interpreted as
-	''justify-self/normal'' if the box is absolutely positioned or has no parent,
-	and as the computed 'justify-items' value of the parent box
+	The <dfn value for="justify-self">auto</dfn> keyword
+	behaves as ''justify-self/normal'' if the box has no parent,
+	or when determining the actual position of an absolutely positioned box.
+	It behaves as the computed 'justify-items' value of the parent box
 	(minus any ''legacy'' keywords)
-	otherwise.
+	otherwise
+	(including when determining the <em>static</em> position
+	of an absolutely positioned box).
 
 	The <dfn value for="justify-self">normal</dfn> keyword
 	represents the “default” alignment for the layout mode.
@@ -1098,10 +1101,14 @@ Block/Cross-Axis Alignment: the 'align-self' property</h3>
 	the box's outer edges are aligned within its <a>alignment container</a>
 	<a href="#alignment-values">as described by its alignment value</a>.
 
-	The <dfn value for="align-self">auto</dfn> keyword is interpreted as
-	''align-self/normal'' if the box is absolutely positioned or has no parent,
-	and as the computed 'align-items' value of the parent box
-	otherwise.
+	The <dfn value for="align-self">auto</dfn> keyword
+	behaves as ''align-self/normal'' if the box has no parent,
+	or when determining the actual position of an absolutely positioned box.
+	It behaves as the computed 'align-items' value of the parent box
+	(minus any ''legacy'' keywords)
+	otherwise
+	(including when determining the <em>static</em> position
+	of an absolutely positioned box).
 
 	The <dfn value for="align-self">normal</dfn> keyword
 	represents the “default” alignment for the layout mode.