bug fix and new features

1. Fix critical bug of undo/redo issue when cut and paste.
2. Add cut/copy/paste/selectAll item to global menu.
3. Add google search item to editor's context menu.
4. optimize editor's context menu build form.
5. optimize to not track document's internal modified status, use
webview's instead.
Fix build issue
Bug fix: user password and language issue

1. forget password when user choose not to save.
2. remove old restart feature.
3. fix language change issue.
i18n update