generic from_file for palettes

src/palette.rs

@@ -28,6 +28,19 @@ impl Palette {
         }
     }
 
+    /// todo result
+    pub fn from_file(path: PathBuf) -> Self {
+        match path.extension().unwrap().to_str().unwrap() {
+            "pal"  => Self::from_jasc(path),
+            "gpl"  => Self::from_gpl(path),
+            "toml" => Self::from(
+                path.file_stem().as_ref().unwrap().to_str().unwrap(),
+                &read_to_string(&path).unwrap()
+            ),
+            _ => panic!("Bad palette")
+        }
+    }
+
     /// JASC .pal format (Paint Shop Pro)
     pub fn from_jasc(path: PathBuf) -> Self {
         let name = path.file_stem().unwrap().to_str().unwrap().into();