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.

commands/server_test.go

@@ -6,11 +6,11 @@ import (
 	"github.com/spf13/viper"
 )
 
-func TestFixUrl(t *testing.T) {
+func TestFixURL(t *testing.T) {
 	type data struct {
 		TestName   string
-		CliBaseUrl string
-		CfgBaseUrl string
+		CLIBaseURL string
+		CfgBaseURL string
 		AppendPort bool
 		Port       int
 		Result     string
@@ -28,11 +28,11 @@ func TestFixUrl(t *testing.T) {
 	}
 
 	for i, test := range tests {
-		BaseUrl = test.CliBaseUrl
-		viper.Set("BaseUrl", test.CfgBaseUrl)
+		BaseURL = test.CLIBaseURL
+		viper.Set("BaseURL", test.CfgBaseURL)
 		serverAppend = test.AppendPort
 		serverPort = test.Port
-		result, err := fixUrl(BaseUrl)
+		result, err := fixURL(BaseURL)
 		if err != nil {
 			t.Errorf("Test #%d %s: unexpected error %s", i, test.TestName, err)
 		}