Sendgrid downgrade

Add version to template variables ( could be useful )

add sendgrid flag to use SMTP

	PORT=80
	cosgo -sendgrid -nolog -quiet -port=$PORT

Update README.md

casgo loves bluemonday

Merge pull request #3 from aerth/captcha

require captcha and csrf token

Merge pull request #2 from aerth/develop

merge in subdomain stuff