pass CSV options to header parser - before, options like delimiter weren't passed so it couldn't read TSVs
eagerly load format-specific methods (instead of waiting for #each to be called)
skip blank lines at the top of CSV files when looking for headers
use new Roo class names (Roo::OpenOffice instead of Roo::Openoffice)
require rubyzip2 for Roo compatibility with Ruby 1.9
v3.0.0.rc2