gitweb: Cleanup Git logo and Git logo target generation

Rename $githelp_url and $githelp_label to $logo_url and $logo_label to
be more obvious what they refer to; while at it add commented out
previous contents (git documentation at kernel.org). Add comment about
logo size.

Use $cgi->a(...) to generate Git logo link; it automatically escapes
attribute values when it is needed.  Escape href attribute using
esc_url instead of (incorrect!) esc_html.

Move styling of git logo <img> element from "style" attribute to CSS
via setting class to "logo".  Perhaps we should set it by id rather
than by class.

Signed-off-by: Jakub Narebski <jnareb@gmail.com>
Signed-off-by: Junio C Hamano <junkio@cox.net>
diff --git a/gitweb/gitweb.css b/gitweb/gitweb.css
index 668e69a..3f62b6d 100644
--- a/gitweb/gitweb.css
+++ b/gitweb/gitweb.css
@@ -16,6 +16,11 @@
 	color: #880000;
 }
 
+img.logo {
+	float: right;
+	border-width: 0px;
+}
+
 div.page_header {
 	height: 25px;
 	padding: 8px;
diff --git a/gitweb/gitweb.perl b/gitweb/gitweb.perl
index cdb09c4..0ec1eef 100755
--- a/gitweb/gitweb.perl
+++ b/gitweb/gitweb.perl
@@ -46,13 +46,16 @@
 
 # URI of default stylesheet
 our $stylesheet = "++GITWEB_CSS++";
-# URI of GIT logo
+# URI of GIT logo (72x27 size)
 our $logo = "++GITWEB_LOGO++";
 # URI of GIT favicon, assumed to be image/png type
 our $favicon = "++GITWEB_FAVICON++";
 
-our $githelp_url = "http://git.or.cz/";
-our $githelp_label = "git homepage";
+# URI and label (title) of GIT logo link
+#our $logo_url = "http://www.kernel.org/pub/software/scm/git/docs/";
+#our $logo_label = "git documentation";
+our $logo_url = "http://git.or.cz/";
+our $logo_label = "git homepage";
 
 # source of projects list
 our $projects_list = "++GITWEB_LIST++";
@@ -1385,11 +1388,9 @@
 	print "</head>\n" .
 	      "<body>\n" .
 	      "<div class=\"page_header\">\n" .
-	      "<a href=\"" . esc_html($githelp_url) .
-	      "\" title=\"" . esc_html($githelp_label) .
-	      "\">" .
-	      "<img src=\"$logo\" width=\"72\" height=\"27\" alt=\"git\" style=\"float:right; border-width:0px;\"/>" .
-	      "</a>\n";
+	      $cgi->a({-href => esc_url($logo_url),
+	               -title => $logo_label},
+	              qq(<img src="$logo" width="72" height="27" alt="git" class="logo"/>));
 	print $cgi->a({-href => esc_url($home_link)}, $home_link_str) . " / ";
 	if (defined $project) {
 		print $cgi->a({-href => href(action=>"summary")}, esc_html($project));