Reduce memory foodprint of BasicDynaBean

Hello, we sometimes use the dynabeans to load rows from the DB and add a small amount of columns (like 2-5 in most cases). In some cases we restore something like 1.000.000 rows.

The current org.apache.commons.beanutils2.BasicDynaBean.values uses a HashMap with default capacity of 16.

The constructor of BasicDynaBean would have the information for a smaller initial size via DynaClass.getDynaProperties().length.

Would it be ok, to create a pull request to provide a smaller initialCapacity of the HashMap to reduce the memory usage to the minimum needed?