v1.4.0

• Add iterator mutable_iterator(const_iterator pos) method.
• Add erase method taking a precalculated hash in parameter similar to lookup functions.
• Reduce default max load factor to 0.9.
• Add mandatory max_bucket_count() method to GrowthPolicy to take into account the possible limitations of the growth policy.
• Fix the number of reserved buckets on range insert (i.e. void insert(InputIt first, InputIt last)). The amount was too low.