Removed the following key bindings from the multiple-cursors layer:
grI evil-mc-make-cursor-in-visual-selection-beg
grA evil-mc-make-cursor-in-visual-selection-end
because they have been added upstream in the evil-mc package.
Changed the changelog.develop entry from saying that they were
added to the layer, to say that they were documented in the layer.
Added evil-mc make cursors from selection key bindings:
grI calls evil-mc-make-cursor-in-visual-selection-beg
grA calls evil-mc-make-cursor-in-visual-selection-end
