+memcached_increment_with_initial() takes a key and keylength and increments
+the value by the offset passed to it. If the object specified by key does
+not exist, one of two things may happen: If the expiration value is
+MEMCACHED_EXPIRATION_NOT_ADD, the operation will fail. For all other
+expiration values, the operation will succeed by seeding the value for that
+key with a initial value to expire with the provided expiration time. The
+flags will be set to zero.The value is then returned via the unsigned int
+value pointer you pass to it.
+
+memcached_decrement_with_initial() takes a key and keylength and decrements
+the value by the offset passed to it. If the object specified by key does
+not exist, one of two things may happen: If the expiration value is
+MEMCACHED_EXPIRATION_NOT_ADD, the operation will fail. For all other
+expiration values, the operation will succeed by seeding the value for that
+key with a initial value to expire with the provided expiration time. The
+flags will be set to zero.The value is then returned via the unsigned int
+value pointer you pass to it.
+
+memcached_increment_by_key(), memcached_decrement_by_key(),
+memcached_increment_with_initial_by_key(), and
+memcached_decrement_with_initial_by_key() are master key equivalents of the
+above.
+