Standardize check for low morale in veh_interact.

In other words, make it work the same way the checks for low skill,
   missing components, etc. work.
Make item::get_remaining_capacity_for_liquid consider fuel for tools

and check for curammo == 0
add check for swimmable terrain instead of only impassable
Draw auto-move preview trail correctly when viewport is offset
apply astyle to changes, and init error correctly
Merge morale check for vehicle construction, tool fuel handling fix, vehicle sinking fix and mouse pathing fix.