Grease 1.3 is the basis for Seaside 3.3

• Pharo 6 support
• Introduce a new GRDynamicVariable which allows for platform specific implementations. On common dialects the implementation should no longer use exceptions/notifications. This can potentially result in a better debugging experience and better lookup performance.
• Add a #thisContext method to GRPlatform for accessing the current execution context even on dialects that do not have a thisContext variable like GemStone/S or VASt.

• You need to provide a GRDynamicVariable class in the platform specific package. Ideally this is a dynamic variable or process/thread local variable that does not rely on exceptions/notifications. If your dialect does not support this you can create an empty subclass of GRNotificationBasedDynamicVariable named GRDynamicVariable.
• You need to provide a GRDialectPlatform >> #thisContext method. If your dialect has a thisContext variable the implementation is a simple as ^ thisContext sender.