Base: Add new icons for fonts and File Manager

Base/etc/FileIconProvider.ini

@@ -1,5 +1,6 @@
 [Icons]
 cplusplus=*.cpp,*.cxx,*.cc,*.c++
+font=*.font
 form=*.frm
 header=*.h,*.hpp,*.hxx,*.hh,*.h++
 html=*.html,*.htm
@@ -16,3 +17,4 @@ python=*.py
 sound=*.wav
 spreadsheet=*.sheets
 text=*.txt
+truetype=*.ttf

Userland/Applications/FileManager/CMakeLists.txt

@@ -9,5 +9,5 @@ set(SOURCES
     PropertiesWindow.cpp
 )
 
-serenity_app(FileManager ICON filetype-folder)
+serenity_app(FileManager ICON app-file-manager)
 target_link_libraries(FileManager LibGUI LibDesktop)

Userland/Applications/FileManager/main.cpp

@@ -731,7 +731,7 @@ int run_in_windowed_mode(RefPtr<Core::ConfigFile> config, String initial_locatio
     go_menu.add_action(go_to_location_action);
 
     auto& help_menu = menubar->add_menu("Help");
-    help_menu.add_action(GUI::CommonActions::make_about_action("File Manager", GUI::Icon::default_icon("filetype-folder"), window));
+    help_menu.add_action(GUI::CommonActions::make_about_action("File Manager", GUI::Icon::default_icon("app-file-manager"), window));
 
     GUI::Application::the()->set_menubar(move(menubar));