create and use Chj::Parse::Mbox::Section
--source-to: copy mbox section instead of 'deparsing' the mime entity
rename higher level warning
change from global::warn to $SIG{__WARN__} for effect on external libs
explain standard_warn
use previous handler (to e.g. make it work with Carp::Always)
fix undefined startpos in mbox section
fixing up pseudo-mbox message heads: turn spaces in header names into '-'
Plain: preserve spaces
Plain: url detection
offer $parents to HTML mappers
add shading level to blockquote
use __WARN__ instead of WARN for normal 'warn' type warnings
fix $parents
fix handling of toplevel text/html or text/enriched entity
parse and decode from, to, cc and subject headers
add array_join
use parsed/decoded from, to, cc, subject in --html-to
Plain: improve whitespace conversion
update MANIFEST