lay out lay in layers

purpose of this plugin is, to lay out and lay in a group of consecutive layers of an image
(a humble kind of collapse and expand groups of layers)
"collapse":
a determinable number of layers (including the active layer) will be stored (layed out) in a new image.
the name of this image is a time stamp ("%Y%m%d-%H%M%S") plus the string ".xcf".
e.g. 20080117-192642.xcf.
the visible layed out layers will be merged down to a single layer in the source image.
the name of this layer is the above mentioned time stamp.
"expand":
look for the open image with the name like the active layer's name of the source image.
fetch all the layers of the layed-out-layers-image and place them above the active layer.
this active layer will not be replaced but switched to invisible.
laylaylay registers itself under Image - Layer - Stack.