Correct initialisms as suggested by golint

First step to use initialisms that golint suggests,
for example:

    Line 116: func GetHtmlRenderer should be GetHTMLRenderer

as see on http://goreportcard.com/report/spf13/hugo

Thanks to @bep for the idea!

Note that command-line flags (cobra and pflag)
as well as struct fields like .BaseUrl and .Url
that are used in Go HTML templates need more work
to maintain backward-compatibility, and thus
are NOT yet dealt with in this commit.

First step in fixing #959.

hugolib/page_permalink_test.go

@@ -16,8 +16,8 @@ func TestPermalink(t *testing.T) {
 		base         template.URL
 		slug         string
 		url          string
-		uglyUrls     bool
-		canonifyUrls bool
+		uglyURLs     bool
+		canonifyURLs bool
 		expectedAbs  string
 		expectedRel  string
 	}{
@@ -42,8 +42,8 @@ func TestPermalink(t *testing.T) {
 	viper.Set("DefaultExtension", "html")
 
 	for i, test := range tests {
-		viper.Set("uglyurls", test.uglyUrls)
-		viper.Set("canonifyurls", test.canonifyUrls)
+		viper.Set("uglyurls", test.uglyURLs)
+		viper.Set("canonifyurls", test.canonifyURLs)
 		p := &Page{
 			Node: Node{
 				UrlPath: UrlPath{