Blender Git Loki

Fix: "Tweak user" red-alert flag was not getting set on strips on active track

The "tweak user" flag used to flag strips using the same action as the active strip
was not getting set on other strips that live on the same track as the active one.
Strips with this flag set are shown with a red colour to indicate that editing the
action may have the unintended consequence of modifying another strip.