Str corrections

Author: pschatzmann

src/AudioBasic/Str.h

@@ -114,7 +114,7 @@ class Str {
             this->maxlen = maxlen;
             this->len = len;
             this->is_const = isConst;
-            if (len==0){
+            if (len==0 && !isConst){
                 this->chars[0] = 0;
             }
         }
@@ -610,6 +610,15 @@ class Str {
             return result;
         }
 
+        /// Converts the string to an long
+        long toLong() {
+            long result = 0;
+            if (!isEmpty()){
+                result = atol(chars);
+            }
+            return result;
+        }
+
         /// Converts the string to lowercase letters
         void toLowerCase(){
             if (chars!=nullptr){