[css-align] Complete changes required by #1001; fixes #1446 and #1445.

Author: fantasai

css-align/Overview.bs

@@ -645,7 +645,7 @@ Content Distribution: the 'align-content' and 'justify-content' properties and '
 
 	<pre class="propdef">
 	Name: place-content
-	Value: <<'align-content'>> <<'justify-content'>>
+	Value: <<'align-content'>> <<'justify-content'>>?
 	Initial: normal
 	Applies to: block containers, flex containers, and grid containers
 	Inherited: no
@@ -902,7 +902,7 @@ Inline/Main-Axis Alignment: the 'justify-self' property</h3>
 
 	<pre class="propdef">
 	Name: justify-self
-	Value: auto | normal | stretch | <<baseline-position>> | [ <<overflow-position>>? && <<self-position>> ]
+	Value: auto | normal | stretch | <<baseline-position>> | <<overflow-position>>? <<self-position>>
 	Initial: auto
 	Applies to: block-level boxes, absolutely-positioned boxes, and grid items
 	Inherited: no
@@ -954,7 +954,7 @@ Inline/Main-Axis Alignment: the 'justify-self' property</h3>
 			[[#baseline-align-self]],
 			and [[#baseline-rules]].
 
-		: <<overflow-position>>? && <<self-position>>
+		: <<overflow-position>>? <<self-position>>
 		::
 			Defined in [[#alignment-values]], above.
 	</dl>
@@ -1129,7 +1129,7 @@ Block/Cross-Axis Alignment: the 'align-self' property</h3>
 
 	<pre class="propdef">
 	Name: align-self
-	Value: auto | normal | stretch | <<baseline-position>> | [ <<overflow-position>>? <<self-position>> ]
+	Value: auto | normal | stretch | <<baseline-position>> | <<overflow-position>>? <<self-position>>
 	Initial: auto
 	Applies to: flex items, grid items, and absolutely-positioned boxes
 	Inherited: no
@@ -1316,7 +1316,7 @@ Self-Alignment Shorthand: the 'place-self' property</h3>
 
 	<pre class="propdef">
 	Name: place-self
-	Value: [ auto | normal | stretch | <<baseline-position>> | <<self-position>> ]{1,2}
+	Value: <<'align-self'>> <<'justify-self'>>?
 	Initial: auto
 	Applies to: block-level boxes, absolutely-positioned boxes, and grid items
 	Inherited: no