imageio: true should be TRUE

this fixes 0d874257deed1469316fe770611e32a989db680c
related to bug #9756
(cherry picked from commit 4e5f76cfd86bfeddb839782070a3a720ec4b5ee6)
masks: allow removal of path/brush nodes in restricted edit mode
(cherry picked from commit 42497e02624d1ace0f6c23a5c72f6d0290cc3984)
Only write the history stack when called from the darkroom.

Indeed there is nothing to save when called from the lighttable
and actually this will erase current history stack of the
selected images.

Better fix for #9340.
(cherry picked from commit c528de79d902e812acf10afcbfd4dd9e526767ae)
Deprecated and remove the "backup" functionality of camera import.
(cherry picked from commit db4e4afd310143ee93f834c3750e49113be8b0c5)