Make load errors more specific to where they are coming from (file/url)

Also include the hash of the project in load errors from the server so we can debug them

src/containers/gui.jsx

@@ -65,7 +65,10 @@ class GUI extends React.Component {
         this.props.vm.stopAll();
     }
     render () {
-        if (this.state.loadingError) throw new Error(`Failed to load project: ${this.state.errorMessage}`);
+        if (this.state.loadingError) {
+            throw new Error(
+                `Failed to load project from server [id=${window.location.hash}]: ${this.state.errorMessage}`);
+        }
         const {
             children,
             fetchingProject,

src/containers/project-loader.jsx

@@ -76,7 +76,10 @@ class ProjectLoader extends React.Component {
         );
     }
     render () {
-        if (this.state.loadingError) throw new Error(`Failed to load project: ${this.state.errorMessage}`);
+        if (this.state.loadingError) {
+            throw new Error(
+                `Failed to load project from file: ${this.state.errorMessage}`);
+        }
         const {
             /* eslint-disable no-unused-vars */
             children,