Backport of JSR 166 errors

http://backport-jsr166.sourceforge.net/

Dawid Kurzyniec's backport of JSR 166

Documented:

DescriptionException TypeEntry MethodWeb pages
NullPointerExceptionConcurrentHashMap.get12
Package namePatterns foundSolution coverageDescription coverage
edu.emory.mathcs.backport.java.util.concurrent14
edu.emory.mathcs.backport.java.util.concurrent.locks1
Package nameClass namePatterns foundSolution coverageDescription coverage
edu.emory.mathcs.backport.java.util.concurrentThreadPoolExecutor$Worker6
edu.emory.mathcs.backport.java.util.concurrentFutureTask3
edu.emory.mathcs.backport.java.util.concurrentThreadPoolExecutor2
edu.emory.mathcs.backport.java.util.concurrentCopyOnWriteArrayList1
edu.emory.mathcs.backport.java.util.concurrentConcurrentHashMap1
edu.emory.mathcs.backport.java.util.concurrentExecutors$RunnableAdapter1
Package nameClass nameMethod namePatterns foundSolution coverage
edu.emory.mathcs.backport.java.util.concurrentConcurrentHashMapget1
Package nameClass nameMethod nameException TypePatterns foundSolution coverage
edu.emory.mathcs.backport.java.util.concurrentConcurrentHashMapgetNullPointerException1