Removed blogUrl param from showBlogPreview(), added new routines for following/unfollowing blogs & feeds

Author: nbradbury

WordPressUtils/src/main/java/org/wordpress/android/util/StringUtils.java

@@ -275,4 +275,17 @@ public static int stringToInt(String s, int defaultValue) {
             return defaultValue;
         }
     }
+
+    public static long stringToLong(String s) {
+        return stringToLong(s, 0L);
+    }
+    public static long stringToLong(String s, long defaultValue) {
+        if (s == null)
+            return defaultValue;
+        try {
+            return Long.valueOf(s);
+        } catch (NumberFormatException e) {
+            return defaultValue;
+        }
+    }
 }