Change actions naming scheme

Use _ instead of capital letters in words for actions names. This will make some other stuff much easier.

src/actions.js

@@ -0,0 +1,18 @@
+const Dialogs = imports.src.dialogs;
+
+var actions = {
+    open_local: {
+        run: (window) => new Dialogs.FileChooser(window),
+        accels: ['<Ctrl>O'],
+    },
+    open_uri: {
+        run: (window) => new Dialogs.UriDialog(window),
+        accels: ['<Ctrl>U'],
+    },
+    prefs: {
+        run: (window) => new Dialogs.PrefsDialog(window),
+    },
+    about: {
+        run: (window) => new Dialogs.AboutDialog(window),
+    }
+};