Initial experiments with adding blockwise visual mode
Initial creation of visual block works!
Some improvements...
Use a Rect for blockwise; movement seems to work properly, now!
Commands successfully work only on first line... now to spread result
Fake blockwise editing using repetition; doesn't work for c, r, etc.

Also, the doesn't combine to a single history entry :(
Use compound action for block selection text operations for proper undo!
Clear selection when leaving blockwise

Not sure if it's "correct," but it fixes the issue where you
get stuck with the wrong caret type after doing s or c, for example
'I' goes to the right place (but doesn't work); A doesn't....

Somehow the blockwise selection is lost...?
Fix 'A' to go to the right place!
Insert and Append in Block mode WORK CORRECTLY WOAH
Fix 'r' command in visual-block mode
Refactor the Blockwise repetition to be more easily reused
Experiment with ChangeOperation; fix some other bugs
Fix eclipse blockwise cursor to use "view" instead of "model" (oops)
Change op repition starts in the right place, but only runs once...
Use util method to check for newline instead of explicit search
Switch active reg back to default after repeat to fix change actions
Implement SwapCase (~) command for Visual Block mode
Fix potential NPE