UTF-7 encode label names when adding/removing GMail IMAP labels
UTF-7 encode label names when adding/removing GMail IMAP labels

Fixes issue #154

matt2003/MailKit,sstraus/MailKit,jamie-dainton/MailKit,eino-makitalo/MailKit,dsbenghe/MailKit,FubarDevelopment/MailKit,nachocove/MailKit,mganss/MailKit,jstedfast/MailKit