Make sure the GetMailAddresses function parses DisplayNames containing a comma correctly

I had a problem where the DisplayName part of an email address contained a comma. I wrote unit tests to ensure the current behavior as well failing unit tests for my scenario. Then I rewrote the GetMailAddresses part. I was wondering why you did something with the ; (semicolon) in your code? Is that part of some spec as I cannot find any examples of email addresses being seperated with semicolons?

In this commit:
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.