Adds the contactFormOnBeforeSend() hook for other plugins to use.
Contact Form 1.3
* Adds the contactFormOnBeforeSend() hook
* Adds a changelong entry to the readme
* Adds a usage block for the contactFormOnBeforeSend() hook
* Updates the version number
Added a ContactFormService, and swapped the contactFormOnBeforeSend plugin hook for a contactForm.onBeforeSend event
Updated the readme
Typo
Added support for multiple email addresses, and tweaked the onBeforeSend event
Updated the readme