check mails, ensure lower case

Small tweaks made for the May 2013 mail blast.
Merge branch 'master' of github.com:Stanford-Online/class2go
merge tool: skip non-ascii chars in input
generate edx course mailing list for c2g to use

Queries the edx database to get enrolled students and then creates a
mailing list for Class2Go to actually send with.  Handles excludes.
Flattens out names with non-ascii characters as best it can.
edx-mailing tool: quote csv output in case names have commas
edx-maillist: comment cleanup
edx-maillist: remove commas, trailing spaces from names
edx-maillist tool: parameterize user
Script for creating optouts in edX from class2go
optout script: just write to stdout, fix quoting
edx query should exclude optouts

Now that bulk mail is released at edX we should exclude the people who
have opted out of communication on that side.  Just decided to do it
server-side for now.
fix downloading csv grades (only want complete examrecords)