v1.5 - stable release

Version 1.5

- calling render() is not necessary when sending emails
- new methods : setFrom(), setTo(), setSubject(), setBody(),
setAttachment()...
- all methods are named in camelCase, no need to set PHPMailer
properties directly
- testMode for saving emails as eml files
- PHPMailer 5.2.6 now included
- updated documentation and examples
- extension is still compatible with old code used with previous
versions