Bug 879511 - [email/IMAP] date-time parsing regex does not accept legal "SP DIGIT" syntax. r=lightsofapollo

land https://github.com/mozilla-b2g/gaia-email-libs-and-more/pull/217
Merge pull request #10269 from asutherland/email-imap-date-parse

Bug 879511 - [email/IMAP] date-time parsing regex does not accept legal "SP DIGIT" syntax. r=lightsofapollo