This is mostly a simple lexical search+replace but the absence of operator< for
std::weak_ptr<T> leads to some complications, particularly with Evoral::Sequence
and ExportPortChannel.
Found via `codespell -q 3 -S *.po,./.git,./share/patchfiles,./libs,./msvc_extra_headers,./share/web_surfaces,*.patch -L ba,buss,busses,discreet,doubleclick,hsi,ontop,ro,scrollin,seh,siz,sord,sur,te,trough,ue`
This doesn't yet correctly fix Pane::constrain_fract() constraints,
when moving the divider, but it does prevent child widgets from
being allocated with a size smaller than their minimum.
This fixes some layout and rendering issues (widgets that have
a too small allocation are not exposed and/or bleed into neighbors)
