resizing issue when resize to minimal dimension with resizer other than right-bottom resizer

[archer0302]

Changes to current unit tests:

1. Instead of testing on a minimal dimension of (0, 0), now testing on a size that's bigger than 0.
2. The calculation of position when node is at minimal dimension was not quite correct, now is expecting the right position.

[steven0x51]

Tested code locally, issue fixed