Remove unnecessary "Add" in the Add context menu

[jack-ii]

These "Add" in the Add submenu on each entry in the eventsheet make no sense and it's harder to read. If you open the menu with the Add button or the "Add..." at the end of the eventsheet, instead of the right mouse button, there are no "Adds".

• [x] Remove "Add" from Add context menu entries

Oh and one more little thing

• [ ] Fix the size of the save confirmation dialog box (or text center if the size is intended)