Send mail function params updated. Version number updated.

The 5th (optional) parameter was preventing email from being sent. This is an update following comments at https://github.com/ericbarnes/Statamic-email-form/pull/19. Given that the 5th param is optional, it has been removed to ensure more generic compatibility.

Also updated version number to represent number of commits.

Set fields names to display ucfirst in the email message.
Merge pull request #22 from aarmitage/master

Send mail function params updated. Version number updated.