ocl: vectors are hard-set to 1, add appropriate "optimisation".
ocl/misc: spacing.
ocl: use 'nf' instead of 'n' in compiled kernel binary name.

It is used as a factor number here (e.g. 10, not 1024).
scrypt: rename `n` to `nfactor`.

`n` is commonly used as a number counter, be verbose as to
what this refers to.
scrypt: remove commented-out magic numbers.
misc: add FIXME for scrypt_test() and scanhash_scrypt().