Add ability to cycle through sprite pieces

[flamewing]

In SonMapEd, you can cycle through the individual sprite pieces of a sprite frame by pressing shift+[ or shift+]. Having the ability to do similar in Flex would be great, even if the keys used are different. As-is, it is impossible to select one sprite if two sprites overlap at the same location.

[kirjavascript]

note to self: if multiple sprite pieces are selected, just change it to just selecting one if this command is used I dont think just shifting the current selection would be useful

[VAdaPEGA]

I'd prefer if a different keyboard shortcut is to be used for this as not all keyboards have [ and ] as individual keys (for example, Portugal's) or add an alternative / key rebind feature