Use pointers instead of copying value
Removed external smtpmail dependency.

Added initial methods for handling To and partial support for FromName.
Golinted
See commit message. Re-write of the mail object removing dependencies.

1. Coverage of 100% in unittests
2. io.Reader is the only way to add attachments from the FS.
3. Email addresses will be validated in the client for To, Bcc, CC.
4. Cc support has been added.
5. Content ID support added.
6. Everything is done by reference.
7. Missing comments and Godoc :(
8. Golinted
Removed CC methods, added HeadersString Method
Removed unused tests and added test for HeaderString
Better error handling and support for headers
Added Tests for Send and newclient
Updated docs
ContentID support
ContentID support
Merging re_write

Higher functionality, unittests, more inline methods with other libs
Removed Godeps