Add IsHome

To determine if a page is the "Home Page" has inspired lots of creativity in the template department.

This commit makes it simpler: IsHome will tell the truth.

hugolib/site_test.go

@@ -16,6 +16,7 @@ import (
 	"github.com/spf13/hugo/target"
 	"github.com/spf13/hugo/tpl"
 	"github.com/spf13/viper"
+	"github.com/stretchr/testify/assert"
 )
 
 const (
@@ -419,6 +420,10 @@ func doTest404ShouldAlwaysHaveUglyUrls(t *testing.T, uglyURLs bool) {
 		{filepath.FromSlash("sitemap.xml"), "<?xml version=\"1.0\" encoding=\"utf-8\" standalone=\"yes\" ?>\n<root>SITEMAP</root>"},
 	}
 
+	for _, p := range s.Pages {
+		assert.False(t, p.IsHome)
+	}
+
 	for _, test := range tests {
 		file, err := hugofs.DestinationFS.Open(test.doc)
 		if err != nil {