Reviewed-by: briangoetz, dl

8024688: further split Map and ConcurrentMap defaults eliminating looping from Map defaults, Map.merge fixes and doc fixes.
Reviewed-by: psandoz, dholmes

Reviewed-by: psandoz, alanb

8024331: j.u.Map.computeIfPresent() default/nondefault implementations don't throw NPE if the remappingFunction is null and the key is absent
Summary: Explicitly check for null remappingFunction parameter.
Reviewed-by: mduigou, forax, psandoz
Contributed-by: NBrian Burkhalter <brian.burkhalter@oracle.com>

Reviewed-by: dl, dholmes, plevart

8016446: Improve forEach/replaceAll for Map, HashMap, Hashtable, IdentityHashMap, WeakHashMap, TreeMap, ConcurrentMap
Reviewed-by: forax, mduigou, psandoz
Contributed-by: NMike Duigou &lt;mike.duigou@oracle.com&gt;, Remi Forax <forax@univ-mlv.fr>

8010122: Add defaults for ConcurrentMap operations to Map
Reviewed-by: darcy, briangoetz, mduigou, dholmes, ulfzibis
Contributed-by: NDoug Lea &lt;dl@cs.oswego.edu&gt;, Henry Jen &lt;henry.jen@oracle.com&gt;, Akhil Arora &lt;akhil.arora@oracle.com&gt;, Peter Levart &lt;peter.levart@gmail.com&gt;, Mike Duigou <mike.duigou@oracle.com>