Renamed GetAddresses to GetMailAddresses.
Made sure that GetMailAddresses finds correct addresses when the DisplayName part contains a comma.
Removed looking for semicolon as I cannot find this in the mail spec and don't have any example mail headers containing semicolons to separate mail addresses.
Merge pull request #126 from jvdvleuten/b6f42005528c189385f666b84a97c541cf103b0e

Make sure the GetMailAddresses function parses DisplayNames containing a comma correctly