Now allows user to pass (eg) boost::array<> for multiple-quotes

Fixed numbers of separators would allow faster performance.
I also use boost::range::find() to check for a match, rather than
the incorrectly-chosen string::find_first_of().
csvparser is now noncopyable, as it would be really confusing!

If you copied the parser, the state would be copied too.
So if the user was incorrectly copying it around, it would be slower
(more copies) and potentially giving incorrect results.

If user wants to move parser around, they should wrap it in a shared_ptr