fix: error of canvas scale.

Signed-off-by: liuyanghejerry <liuyanghejerry@126.com>
bugfix: canvascontainer cursor render;
update: panoramawidget and canvascontainer for better view;
bugfix: sketch brush shortcut.

Signed-off-by: liuyanghejerry <liuyanghejerry@126.com>
bugfix: rapid change brush glitch;
add: auto regenerate thumbnail in panoramawidget;
add: Mac OS X icon;
minor changes;

Signed-off-by: liuyanghejerry <liuyanghejerry@126.com>
update: more efficient panoramawidget.

Signed-off-by: liuyanghejerry <liuyanghejerry@126.com>
update: less memory leak in canvas;
update: enable control in panoramawidget;
other minor changes.

Signed-off-by: liuyanghejerry <liuyanghejerry@126.com>
add: singleshortcut.

Signed-off-by: liuyanghejerry <liuyanghejerry@126.com>