Fix #41

Fix #44

Fix #43

Fix #45

For #45

For #45

For #44

For #44

For #43

Fix #42

For #42

For #41

For #41

For #41

For #41

Needed for two-dimensional Gaussian model

For #41

For #41

For #41

Fix #38

Setting editor to CellEditor makes the column read-only for user even
if "editable=True" for the entire DataTable

Fix #40

Fix #39