#1416 Lost indentation after comment/uncomment block

[Nizamov Shawkat]

1) select some text and note its indentation position.
2) comment it using "add comment block" or Ctrl+4.
3) uncomment it using "remove comment block" or Ctrl+5.
4) observe that text is shifted to the right by one space character, that was inserted during the step 2 but not removed in the step 3.

This behavior I observe for more than 1 year (Linux and Windows, Eclipse 3.6 and 3.7, actual Pydev versions), so it should be very well reproducible.