Log Message:
Changes 8.6.3:
Cocoa: Crash after [$button destroy]
Cocoa: button and scroll display fixes
Cocoa: improved drawing performance
Phony button clicks from browsers to plugin
[text] elide changes advance epoch
fix PNG transparency appearance
Win: updated file dialogs
OSX: Improved ttk notebook tab metrics for Yosemite
[scale -digits $bigValue] segfault
[scale] handling of negative resolution