Request for Bulk Approval - backport test stabilization change from JDK8

[Chris Hegarty]

This is a bulk request for approval to backport some test stabilization 
change from JDK8 to 7u-dev. There are many more, this is just a start!

All changes are in JDK8, and all changesets are identical.

7076756: TEST_BUG: com/sun/jdi/BreakpointWithFullGC.sh fails to cleanup 
in Cygwin
http://hg.openjdk.java.net/jdk8/tl/jdk/rev/cf203f293b4e

7105929: java/util/concurrent/FutureTask/BlockingTaskExecutor.java fails 
on solaris sparc
http://hg.openjdk.java.net/jdk8/tl/jdk/rev/c64c815974ff

8002297: sun/net/www/protocol/http/StackTraceTest.java fails intermittently
http://hg.openjdk.java.net/jdk8/tl/jdk/rev/157506182fa7

6736316: Timeout value in 
java/util/concurrent/locks/Lock/FlakyMutex.java is insufficient
http://hg.openjdk.java.net/jdk8/tl/jdk/rev/7289599216fe

6957683: test/java/util/concurrent/ThreadPoolExecutor/Custom.java failing
http://hg.openjdk.java.net/jdk8/tl/jdk/rev/72d8f91514d1

7030573: test/java/io/FileInputStream/LargeFileAvailable.java fails when 
there is insufficient disk space
http://hg.openjdk.java.net/jdk8/tl/jdk/rev/74c92c3e66ad

7152856: TEST_BUG: sun/net/www/protocol/jar/B4957695.java failing on Windows
http://hg.openjdk.java.net/jdk8/tl/jdk/rev/31c15e2f51ba

7162385: TEST_BUG: sun/net/www/protocol/jar/B4957695.java failing again
http://hg.openjdk.java.net/jdk8/tl/jdk/rev/bc51d0569ccd

6818464: TEST_BUG: java/util/Timer/KillThread.java failing intermittently
http://hg.openjdk.java.net/jdk8/tl/jdk/rev/c98235762b30

6860309: TEST_BUG: Insufficient sleep time in 
java/lang/Runtime/exec/StreamsSurviveDestroy.java
http://hg.openjdk.java.net/jdk8/tl/jdk/rev/450c17e4808d

-Chris.