doc: don't wrap package names in directory listing

Fixes #3522.

R=golang-dev, dsymonds
CC=golang-dev
https://golang.org/cl/6063054

doc/style.css

@@ -108,7 +108,9 @@ table.dir td {
 	word-wrap: break-word;
 	vertical-align: top;
 }
-
+div#page.wide table.dir td.name {
+	white-space: nowrap;
+}
 .alert {
 	color: #AA0000;
 }
@@ -388,4 +390,3 @@ img.gopher {
 	margin-bottom: -120px;
 }
 h2 { clear: right; }
-

lib/godoc/package.html

@@ -192,14 +192,14 @@
 		{{if $.DirFlat}}
 			{{if .HasPkg}}
 				<tr>
-				<td><a href="{{html .Path}}">{{html .Path}}</a></td>
+				<td class="name"><a href="{{html .Path}}">{{html .Path}}</a></td>
 				<td>&nbsp;&nbsp;&nbsp;&nbsp;</td>
 				<td style="width: auto">{{html .Synopsis}}</td>
 				</tr>
 			{{end}}
 		{{else}}
 			<tr>
-			<td>{{repeat `&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;` .Depth}}<a href="{{html .Path}}">{{html .Name}}</a></td>
+			<td class="name">{{repeat `&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;` .Depth}}<a href="{{html .Path}}">{{html .Name}}</a></td>
 			<td>&nbsp;&nbsp;&nbsp;&nbsp;</td>
 			<td style="width: auto">{{html .Synopsis}}</td>
 			</tr>