$headers should remain a string

$headers variable should remain a string + added return and newline to
end of line
From should come before CC

From needs to come before the CC in the header. Also I changed From to a
string instead of an array as I think there should be only one from.
added return value for send method

Send wasn't returning a value as it used to so I added an else statement
to return true
Merge pull request #3 from cameronfraser/master

Fixed mailer class so it is now functional