Print: correct tab order in the options widget

Tab order should begin from the topmost widget and then
descend towards the bottom end of the dialog.

Signed-off-by: Lubomir I. Ivanov <neolit123@gmail.com>
Print: connect all the options widgets to slots

By connecting to slots we always modify values at a previously
set 'struct options' pointer.

Also have the setup of slots and pre-set values in a
separate setup(struct options *) function.

Signed-off-by: Lubomir I. Ivanov <neolit123@gmail.com>