Also updates a lot of other things (brush size now independent from
scale factor, split some files, and a lot other things; removed erase
safeguard as now erase is supported by undo/redo; tried adding github
prettier autoformatting to pull requests;
may have some other things as well
Signed-off-by: Victor Seiji Hariki <victorseijih@gmail.com>
Former-commit-id: 0ba21f23c69f9dca2c3189a838b945900b01f81d
Implements command pattern for providing edit history capabilities to
editing. For now, no implementation is done to support keyboard
shortcuts, so the buttons are the only way to navigate. Also, only image
insertion is supported for now. Waiting for the masking updates to
implement masking history.
Signed-off-by: Victor Seiji Hariki <victorseijih@gmail.com>
