[composer] Allow clicking-dragging to set size of labels, pictures, legends ands tables when adding them to a composition (fix #9821)
[composer] Mark project dirty when additional composer related changes occur (fix #7470)
Trying to fix #10164 (crash on zoom in/out)

This happens due to infinite recursion when syncing extent between
map canvas and map renderer. Not entirely sure why, seems to happen
only on 32bit systems.
Event layer function: catch various error cases for line offsets
fixing some UI bugs in settings dialog

Signed-off-by: Werner Macho <werner.macho@gmail.com>
[layertree] Do not start editing in tree view too easily
[layertree] Only add layers to layer tree if the client wanted that
[layertree] Fix python issues with addLayer()