Implemented loading Settings from file. Implemented mining of Keystore (key pair). Changed Transaction structure a lot. Added an icon to windows build. Changed some HTML.

src/context.rs

@@ -1,5 +1,9 @@
 use crate::{Keystore, Blockchain};
 use std::collections::HashMap;
+use serde::{Serialize, Deserialize, Serializer, Deserializer};
+use serde::de::Error;
+use std::fs::File;
+use std::io::Read;
 
 pub struct Context {
     pub(crate) settings: Settings,
@@ -38,21 +42,33 @@ impl Context {
     pub fn get_blockchain(&self) -> &Blockchain {
         &self.blockchain
     }
-
-    pub fn add_salt(&mut self, name: String, salt: String) {
-        &self.settings.salts.insert(name, salt);
-    }
 }
 
+#[derive(Clone, Debug, Serialize, Deserialize)]
 pub struct Settings {
     pub chain_id: u32,
     pub version: u32,
-    salts: HashMap<String, String>
+    pub key_file: String
 }
 
 impl Settings {
-    /// TODO parse settings
-    pub fn new<S: Into<String>>(settings: S) -> Settings {
-        Settings { chain_id: 42, version: 0, salts: HashMap::new() }
+    pub fn new<S: Into<String>>(settings: S) -> serde_json::Result<Settings> {
+        serde_json::from_str(&settings.into())
+    }
+
+    pub fn load(file_name: &str) -> Option<Settings> {
+        match File::open(file_name) {
+            Ok(mut file) => {
+                let mut text = String::new();
+                file.read_to_string(&mut text);
+                let loaded = serde_json::from_str(&text);
+                return if loaded.is_ok() {
+                    Some(loaded.unwrap())
+                } else {
+                    None
+                }
+            },
+            Err(..) => None
+        }
     }
 }