csv.lua: fix typos
csv.lua: move some variable definitions closer to their use (the aim here is to move find and sub out into a buffer object)
test.lua: add an exclamation mark to the end of newlines so that they're explicit
csv.lua: this all doesn't work with small buffer sizes.  Whoops.  Made tests at small buffer sizes and fixed the problem
Test at all buffer sizes from 1 to 16.  Fix the resulting bug when an embedded quote straddles two buffer blocks