Character events are created via a dedicated 'Event' constructor that
takes an 'Event:Utf8' object as argument. Internally, the character is
kept in the '_code' member. The 'Utf8' value can by retrieved by the
recipient via the new 'utf8' method.
Issue #2264
This patch changes the top-level directory layout as a preparatory
step for improving the tools for managing 3rd-party source codes.
The rationale is described in the issue referenced below.
Issue #1082
