Update versioneer for Python 3.12 compat

Update versioneer for Python 3.12 compat

Fix EntryPoint::main_event being non-optional

The main event of an entry point is actually optional.

repr_util: Avoid recursion in main traverse loop

Prevents stack overflows on larger flowcharts

timeline: Fix cut structure

The float is not a duration; it seems to be the start time.

timeline: Fix cut structure

The float is not a duration; it seems to be the start time.

v0.13.0

Timelines are now supported! There are still some unknown fields, but
the library should now be able to read most if not all event timelines
and generate them from scratch.

This initial implementation has been tested with every single timeline
in The Legend of Zelda: Breath of the Wild and Splatoon 2.

Move "flowchart to graph" logic (from eventeditor)

This could be reused from a non-GUI program.

Use versioneer for versioning

Bump version