// This is similar to StrCat, but safer and more flexible because
// MergeStrings allocates memory that's the correct size for the
// new merged string, so it can take a NULL *First and it cleans
// This is similar to StrCat, but safer and more flexible because
// MergeStrings allocates memory that's the correct size for the
// new merged string, so it can take a NULL *First and it cleans