remove unused var
no-slip backward compatibility

when phParAdapt writes down a no-slip condition,
the user gives some random but non-zero direction
vector. This extra bit of code carries that vector
around so we can dump it in the BC array for compatibility.
number nBC from 1 to begin with

Trying to get rid of the rather brain-dead
practice of making a new array just to add 1
to all its members. add 1 in the original assignment.
ensure vector normalization