Is there a way to join two strips into one? For example, If you cut a strip in two, do some other stuff and then realize, you want to undo the cut or something; I found how to groups strips, but not how to actually merge them into one.
For strip splited by "Cut" (K) - "Erase" (X) second part of strip and extend the end point manually or by "Snap to Playhead" (Shift+S)
For strip splited by "Hold Cut" (Shift+K) go to properties panel (N) and change "Hold Offset End" to zero (or what ever number that fits to a gap).
There's no need for a separate option as it's automatic. First, upload a movie strip. Then add another and put it where the first one ends. Render under a selected name and extention. Done.