Basically we know that if we are using mixing, compositor will be
able to do video conversion and scaling for us, so avoid adding those
usless elements.
This optimizes a lot caps negotiation for deeply nested timelines.
Export GES library API in headers when we're building the
library itself, otherwise import the API from the headers.
This fixes linker warnings on Windows when building with MSVC.
Fix up some missing config.h includes when building the lib which
is needed to get the export api define from config.h
Fixes https://gitlab.freedesktop.org/gstreamer/gst-editing-services/issues/42
g-ir-scanner includes section docs as class/interface docs if the section name is equal to the lowercase type name.
Since all the documentation is in section blocks, rename them to match the type names.
https://bugzilla.gnome.org/show_bug.cgi?id=727776
