Add support for a simpler filename format

Also make this the default when one doesn't have a title.

This is important as now the filename is far more visible with the new
standard view.

lib/core/note_fileName.dart

@@ -9,11 +9,13 @@ String getFileName(Note note) {
   var date =
       note.created ?? note.modified ?? note.fileLastModified ?? DateTime.now();
   switch (Settings.instance.noteFileNameFormat) {
+    case NoteFileNameFormat.SimpleDate:
+      return toSimpleDateTime(date);
     case NoteFileNameFormat.FromTitle:
       if (note.title.isNotEmpty) {
         return buildTitleFileName(note.parent.folderPath, note.title);
       } else {
-        return toIso8601WithTimezone(date) + ".md";
+        return toSimpleDateTime(date) + ".md";
       }
       break;
     case NoteFileNameFormat.Iso8601:

lib/folder_views/standard_view.dart

@@ -38,7 +38,9 @@ class StandardView extends StatelessWidget {
     if (title == null || title.isEmpty) {
       title = note.fileName;
     }
-    Widget titleWidget = Text(title, style: textTheme.title);
+    var titleTheme =
+        textTheme.title.copyWith(fontSize: textTheme.title.fontSize * 0.95);
+    Widget titleWidget = Text(title, style: titleTheme);
     Widget trailing;
 
     var date = note.modified ?? note.created;

lib/settings.dart

@@ -107,10 +107,13 @@ class NoteFileNameFormat {
   static const Iso8601WithTimeZoneWithoutColon = NoteFileNameFormat(
       "Iso8601WithTimeZoneWithoutColon", "ISO8601 without Colons");
   static const FromTitle = NoteFileNameFormat("FromTitle", "Title");
+  static const SimpleDate =
+      NoteFileNameFormat("SimpleDate", "yyyy-mm-dd-hh-mm-ss");
 
   static const Default = FromTitle;
 
   static const options = <NoteFileNameFormat>[
+    SimpleDate,
     FromTitle,
     Iso8601,
     Iso8601WithTimeZone,

lib/utils/datetime.dart

@@ -1,6 +1,10 @@
 import 'dart:core';
 import 'package:intl/intl.dart';
 
+String toSimpleDateTime(DateTime dt) {
+  return DateFormat("yyyy-MM-dd-HH-mm-ss").format(dt);
+}
+
 String toIso8601(DateTime dt) {
   return DateFormat("yyyy-MM-ddTHH:mm:ss").format(dt);
 }