Escape the Subject: header using RFC2047

Incorporates the encoding code from rfc2047.erl from Zotonic to encode
the Subject: header.
Add parser for RFC 822-style address lists; encode all header values with RFC2047.
Add test with decode_header
Only report that gen_smtp is listening when it actually is doing that.
Move trap_exit to the beginning of the init call.
Merge pull request #35 from mmzeeman/init_error_logger

Don't tell error_logger that gen_smtp_server is listening when it is not.
Merge pull request #30 from zotonic/zotonic-subject-encoding

Escape the Subject: header using RFC2047
Handle lowercase base64 prompts for SMTP AUTH. Fixes #37
Fix long email address test
If TLS upgrade crashes then try again without SSL.
A crash can happen on servers with self-signed certificates.
Fix 'EXIT' tuple, no pid here.
Add missing catch (where did that one go?)
Let binstr handle correctly an empty list. Thanks to dLuna.  Fixes #42.
Merge branch 'mw-ssl-upgrade-crash' of git://github.com/zotonic/gen_smtp into zotonic-mw-ssl-upgrade-crash
Added 'make test' command for simple eunit testing with ssl and iconv