masks: first steps for restricted masks edit mode
noise profile: canon eos 1100D is eos REBEL T3
noise profile: power shot s95 by pawel zogal
masks: implement restricted edit mode

you enter restricted edit mode by CONTROL-click on the "show masks and edit"
icon. in restricted edit mode shapes are protected against accidental deleting,
shifting and enlarging/shrinking. you can still act on single nodes and on the
feathering border. main purpose: eases fine-tuning of shapes (esp. path shapes).
Merge branch 'mymasks'
blending: repair most of blendop parameter sets that got broken recently

breaking of parameter sets did happen when legacy history stacks were
converted to the new structure by the recent development branch. this commit
allows darktable to automatically fix most of the broken blendop parameter
structures (see bug #9466)
lens iop: Enable by default, and automatically set scale.