Dashboard: Added gpio pin toggle.

Signed-off-by: matematik7 <domen.ipavec@z-v.si>
Dashboard: Added gpio polling for updating values.

Signed-off-by: matematik7 <domen.ipavec@z-v.si>
Dashboard: Applied proper bootstrap formatting to forms.

Signed-off-by: matematik7 <domen.ipavec@z-v.si>
Dashboard: Added page for serial interface.

Signed-off-by: matematik7 <domen.ipavec@z-v.si>