We want this in sysprof.h (without UI components) so that we
can use it to filter things in profilers. Therefore, we don't
need to make it namespaced to "visualizers" since a time range
selection is a fairly straightforward, and non-UI confined
implementation.
This is a major redesign a modernization of Sysprof. The core data
structures and design are largely the same, but it has been ported to
Gtk3 and has lots of additions that should make your profiling experience
smoother. Especially for those that are new to profiling.
There are some very simple help docs added, but we really need the
experts to come in and write some documentation here.
