don't use AtomicReferenceFieldUpdater — field name could be changed, use our util class

IDEA-123653 NCDFE Could not initialize class com.intellij.javascript.debugger.nashorn.NashornScope
IDEA-123652 EIE at com.intellij.javascript.debugger.nashorn.NashornCallFrame
(cherry picked from commit 79a999d)
Reusing offscreen image to increase performance.
(cherry picked from commit c26198d)
Icons from option panel, cosmetic changes, magic numbers eliminated.
(cherry picked from commit 26cf621)
jdk 1.6 painting
(cherry picked from commit 12757b7)
Painting optimisation
(cherry picked from commit e66d2cb)
Painting on retina
(cherry picked from commit 2a938a0)
Focuses, draggability on mac + jdk6. The messages are enabled with jdk8 and jdk6
(cherry picked from commit 00cf2c9)
Sheets are added to the ide modality.
(cherry picked from commit d7f97b4)
Eliminating ugly black window with jdk7 and jdk8.
(cherry picked from commit 446b34c)
Better "do not ask" checkbox re-layout.
(cherry picked from commit 6495aaa)
Typo
(cherry picked from commit d9a27f7)
IDEA-122869 Change signature: unreadable message
(cherry picked from commit d134cea)
IDEA-122866 'Terminate the process after disconnect' checkbox is switch off by default
(cherry picked from commit 44818b4)
IDEA-122852 Mac Messages: underscore (broken mnemonic) on some buttons
(cherry picked from commit 904069b)
Better approach for IDEA-122869 Change signature: unreadable message
(cherry picked from commit 0db5440)
Initial value of "do not ask" option has not been honored
(cherry picked from commit 71a9f36)
NPE
(cherry picked from commit 00d1685)
IDEA-122851 Mac Messages on Java 6: sometimes message doesn't get focus
(cherry picked from commit 190c324)
IDEA-121539 New Mac Messages: Yes/No messages have buttons in wrong order
(cherry picked from commit a35bcae)
We still need to set a focused button, but now we can use requestFocusInWindow to prevent focus stealing. Jdk6 does not return focus to the modal blocker properly, so we use the requestFocus conditionally.
(cherry picked from commit b927ac9)