Fix Table Action buttons

[Aung Khant]

Dear Fred and developers,

The table action buttons:

	1. Insert Row
	2. Delete Rows
	3. Insert Column
	4. Delete Columns
	5. Insert Cell
	6. Delete Cells
	7. Merge Cells
	8. Split Cells

should be disabled when user hasn't drawn a table yet or when he doesn't focus a table.

Thank you so much for your time, consideration and hardwork.

[Alfonso Martínez de Lizarrondo]

This is fixed in the nightlies. dup of #1019