Implement scenery tool

[nedik]

In PolyWorks it works like this:

1. RMB opens a list with found sceneries
2. in normal mode, it places a new scenery

list of found sceneries looks like this:

Additional frame with scenery options:

If "Rotate" is selected, after placing a new scenery user can rotate it.
If "Scale" is selected, after placing a new scenery and rotating (if selected too) user can scale it.