Change direction of polyline / Connecting two polylines

Is there a way to change the start/end point of a polyline? I need this in order to optimize the paths a CAM program is calculating out of the .dxf file.

Also is there a way to connect two polylines into one (given that the endpoint of one polyline is the same as the startpoint of another...).

Thanks,
Robert

"Is there a way to change the start/end point of a polyline? I need this in order to optimize the paths a CAM program is calculating out of the .dxf file."

Just click on the polyline and move the blue point where you want them to be.

"Also is there a way to connect two polylines into one (given that the endpoint of one polyline is the same as the startpoint of another...)."

Just use the snap function "Snap on Endpoints" and there you go.
Snap->Snap on Endpoints
or
press this button

I am afraid, my question was not clear enough. I do no how to manipulate polylines of course, but I wanted a simple (one-click) way to swap their direction (without redoing the whole polyline).

And by connecting two polylines I meant to connect to distinct polyline into one, so that when you click on the resulting polyline, all of the segments are selected (and the resulting .dxf file will have a single polyline object that will result in a single move in the CAM software...).

Anyway I started coding a plugin and tried to improve on the line handles (configurable color) and posted a patch to the dev-forum ;-).