Remove email quotes (>) when searching for incoming email delimiters. #2852 #6628

Changes the email truncation so a delimiter can be prefixed by email
quotes or spaces ("> Eric said...").  This will let it be combined with
a "--- Reply above ---" delimiter to match "> --- Reply above ---"

git-svn-id: svn+ssh://rubyforge.org/var/svn/redmine/trunk@4361 e93f8b46-1217-0410-a6f0-8f06a7374b81