add support for transactional html/text emails

- Add support for welcome email on user creation (both OAuth and password users)
- Add support for html/text templating on verify email.
- Add support for html/text templating on reset password.
- Add handlers for converting Handlebars templates to HTML and text (template agnostic).
- Add helper function sendEmail() for compiling and sending templates via Email.send() (SMTP).

imports/modules/get-oauth-profile.js

@@ -0,0 +1,42 @@
+const parseGoogleData = service => {
+  return {
+    email: service.email,
+    name: {
+      first: service.given_name,
+      last: service.family_name,
+    },
+  };
+};
+
+const parseGithubData = (profile, service) => {
+  const name = profile.name.split(' ');
+  return {
+    email: service.email,
+    name: {
+      first: name[0],
+      last: name[1],
+    },
+  };
+};
+
+const parseFacebookData = service => {
+  return {
+    email: service.email,
+    name: {
+      first: service.first_name,
+      last: service.last_name,
+    },
+  };
+};
+
+const getDataForService = (profile, services) => {
+  if (services.facebook) return parseFacebookData(services.facebook);
+  if (services.github) return parseGithubData(profile, services.github);
+  if (services.google) return parseGoogleData(services.google);
+};
+
+export default (options, user) => {
+  const isOAuth = !options.password;
+  const serviceData = isOAuth ? getDataForService(options.profile, user.services) : null;
+  return isOAuth ? serviceData : null;
+};