Fixups for GdkEvent -> Rapicorn::event translations.
Fixups for GdkEvent -> Rapicorn::event translations.

* rapicorn/viewport-gtk.cc: fixed extraction of X time, coordinates and
keyboard modifiers from events in rapicorn_viewport_event_context().
ignore events that are known to deliver bogus data. support coordinate
extraction from parent and child windows with translate_along_ancestry(),
a new function for GdkWindow coordinate translation.

tim-janik/rapicorn,tim-janik/rapicorn,tim-janik/rapicorn,tim-janik/rapicorn,tim-janik/rapicorn