Add possibility to ignore certificate chains

For test installation of Cloudstack we might be running with a broken
certificate. Add an option to pass through an option to TLS. Please
note that this should only be used for testing.

Also rename CloudStack to Cloudstack in all comments.

Author: Peter Jönsson

client.go

@@ -3,6 +3,7 @@ package gopherstack
 import (
 	"crypto/hmac"
 	"crypto/sha1"
+	"crypto/tls"
 	"encoding/base64"
 	"encoding/json"
 	"errors"
@@ -26,11 +27,12 @@ type CloudStackClient struct {
 	Secret string
 }
 
-// Creates a new client for communicating with CloudStack
-func (cloudstack CloudStackClient) New(apiurl string, apikey string, secret string) *CloudStackClient {
+// Creates a new client for communicating with Cloudstack
+func (cloudstack CloudStackClient) New(apiurl string, apikey string, secret string, insecureskipverify bool) *CloudStackClient {
 	c := &CloudStackClient{
 		client: &http.Client{
 			Transport: &http.Transport{
+				TLSClientConfig: &tls.Config{InsecureSkipVerify: insecureskipverify},
 				Proxy: http.ProxyFromEnvironment,
 			},
 		},
@@ -50,9 +52,9 @@ func NewRequest(c CloudStackClient, request string, params url.Values) (interfac
 
 	// Generate signature for API call
 	// * Serialize parameters and sort them by key, done by Encode()
-	// * Use byte sequence for '+' character as CloudStack requires this
+	// * Use byte sequence for '+' character as Cloudstack requires this
 	// * Convert the entire argument string to lowercase
-	// * Calculate HMAC SHA1 of argument string with CloudStack secret
+	// * Calculate HMAC SHA1 of argument string with Cloudstack secret
 	// * URL encode the string and convert to base64
 	s := params.Encode()
 	s2 := strings.Replace(s, "+", "%20", -1)
@@ -63,7 +65,7 @@ func NewRequest(c CloudStackClient, request string, params url.Values) (interfac
 	signature = url.QueryEscape(signature)
 
 	// Create the final URL before we issue the request
-	// For some reason CloudStack refuses to accept '+' as a space character so we byte escape it instead.
+	// For some reason Cloudstack refuses to accept '+' as a space character so we byte escape it instead.
 	url := c.BaseURL + "?" + s2 + "&signature=" + signature
 
 	log.Printf("Calling %s ", url)
@@ -79,7 +81,7 @@ func NewRequest(c CloudStackClient, request string, params url.Values) (interfac
 		return nil, err
 	}
 
-	log.Printf("response from cloudstack: %d - %s", resp.StatusCode, body)
+	log.Printf("Response from Cloudstack: %d - %s", resp.StatusCode, body)
 	if resp.StatusCode != 200 {
 		err = errors.New(fmt.Sprintf("Received HTTP client/server error from CloudStack: %d", resp.StatusCode))
 		return nil, err