patch 9.0.0741: cannot specify an ID for each item with prop_add_list()

Problem:    Cannot specify an ID for each item with prop_add_list(). (Sergey
            Vlasov)
Solution:   Add an optional fifth number to the item. (closes #11360)
diff --git a/runtime/doc/textprop.txt b/runtime/doc/textprop.txt
index 5a849fe..4aa00ac 100644
--- a/runtime/doc/textprop.txt
+++ b/runtime/doc/textprop.txt
@@ -225,7 +225,7 @@
 			GetLnum()->prop_add(col, props)
 <
 						*prop_add_list()*
-prop_add_list({props}, [[{lnum}, {col}, {end-lnum}, {end-col}], ...])
+prop_add_list({props}, [{item}, ...])
 		Similar to prop_add(), but attaches a text property at
 		multiple positions in a buffer.
 
@@ -237,12 +237,18 @@
 		   type		name of the text property type
 		All fields except "type" are optional.
 
-		The second argument is a List of Lists where each list
-		specifies the starting and ending position of the text.  The
-		first two items {lnum} and {col} specify the starting position
-		of the text where the property will be attached and the last
-		two items {end-lnum} and {end-col} specify the position just
-		after the text.
+		The second argument is a List of items, where each {item} is a
+		list that specifies the starting and ending position of the
+		text: [{lnum}, {col}, {end-lnum}, {end-col}]
+		or:   [{lnum}, {col}, {end-lnum}, {end-col}, {id}]
+
+		The first two items {lnum} and {col} specify the starting
+		position of the text where the property will be attached.
+		The next two items {end-lnum} and {end-col} specify the
+		position just after the text.
+		An optional fifth item {id} can be used to give a different ID
+		to a property.  When omitted the ID from {props} is used,
+		falling back to zero if none are present.
 
 		It is not possible to add a text property with a "text" field
 		here.