advotracker: reorganize the project using a crate based structure

* advotracker: the framework project
* crate/advotrackerdb: implementation of the database backend
* crate/advotrackerd: implementation of the backend (daemon)
* crate/adovtracker: implementaton of the application (CLI and GUI)

Signed-off-by: Ralf Zerres <ralf.zerres@networkx.de>

crates/advotracker_client/examples/email_test.rs

@@ -0,0 +1,40 @@
+use lettre::{
+    transport::smtp::authentication::Credentials,
+    Message, SmtpTransport, Transport,
+};
+
+fn main() {
+    let email = Message::builder()
+        .from("Info <info@networkx.de>".parse().unwrap())
+        .reply_to("Support <support@networkx.de>".parse().unwrap())
+        .to("Ralf Zerres <ralf.zerres@networkx.de>".parse().unwrap())
+        .subject("Eine advotracker eMail")
+        .body("Eine neue advotracker eMail!".to_string())
+        .unwrap();
+
+    // Create credential for remote authentication (username, password)
+    //let creds = Credentials::new("ralf.zerres@networkx.de".to_string(), "dekifjgh".to_string());
+    let creds = Credentials::new("ralf.zerres.de@gmail.com".to_string(), "20jacara03".to_string());
+
+    // Open a remote connection to relay server
+    //let mailer = SmtpTransport::relay("nwxex.networkx.de")
+    let mailer = SmtpTransport::relay("smtp.gmail.com")
+        .unwrap()
+        .credentials(creds)
+        .build();
+
+    // Open a remote connection to gmail using STARTTLS
+    // let mailer = SmtpTransport::starttls_relay("nwxex.networkx.de")
+    //     .unwrap()
+    //     .credentials(creds)
+    //     .build();
+
+    // Open a local connection on port 25
+    //let mailer = SmtpTransport::unencrypted_localhost();
+
+    // Send the email
+    match mailer.send(&email) {
+        Ok(_) => println!("Email sent successfully!"),
+        Err(e) => panic!("Could not send email: {:?}", e),
+    }
+}