Reg->6.0.0b2: Block selection bugs

When indenting Python code using block selection, it seems there a number of issues, fex:

1) Shrinking selection does not work:

• In the attached example, place cursor at line 3 ( def f1(a): )
• Press ALT-Cursor down several times to create a block selection
• Press ALT-Cursor up once
• Expected: Line is unselected
• Actual: Entire block is extended over top

2) Semi-Smart behaviour with short lines:

• In the example, place cursor at line 3, column2
• Press ALT-Cursor down several times until end of function 2 reached
• Note at the end of the functions, selection bar is at col 1 instead of 2
• Press Del to outdent
• Expected: Everything moves one column left
• Actual: Separating blank line between funcs disappears, duplicated selection cursors appear

Creator 5 used to be smarter here, you could block select over shorter lines.

When toying around and moving things around, there are tons of other small bugs
and weird behaviours.