Button "Delete" in "Node properties - Parents" initially disabled

[Manuel Luque]

Button "Delete" in tab "Parents" of "Node properties" is disabled when the tab is initially shown after "double-clicking" on the node. It is enabled only if the user "adds" parents through the button "+ Add" and then goes back to the tab.

[Miguel Ángel Artaso Landa]

Additionally, the left column saying "..." in each cell should be hidden.

[Miguel Ángel Artaso Landa]

The new functionality is set as follows: the button appears initially disabled but is enabled whenever the user clics on a parent of the node in the list. When a parent is deleted, the button is disabled again. There is no reason to have the button enabled unless a parent is selected, as no action is possible in that case. Also, the column saying "..." is now properly hidden.