Welcome dialog tweaks

* The welcome dialog is now first-run only (unless the user's
  preferences are reset). This also affects the pre-release notice
  dialog as well.

* Some formatting was changed (e.g. header types).

* Some text was changed too. For example, the 'Manual' link was changed
  to 'Audacity Manual'.

src/HelpText.cpp

@@ -237,25 +237,29 @@ static wxString HelpTextBuiltIn( const wxString & Key )
          << wxT(" [[https://forum.audacityteam.org/|Forum]] - for large knowledge base on using Audacity.")
          << wxT("</li></ul>")
 #else
-         << wxT("<center><h2>Saucedacity ")
-         << AUDACITY_VERSION_STRING
-         << wxT("</h2><h3>")
+         << wxT("<center><h2>")
+         << XO("Welcome to Saucedacity!")
+         << wxT("</h2></center><br>")
+
+         /* i18n-hint: %s is the program's version string */
+         << XO("You are using Saucedacity %s. Saucedacity is based off of Audacity").Format(AUDACITY_VERSION_STRING)
+         << wxT("<center><h2>")
          << XO("Need Help?")
-         << wxT("</h3></center>")
-         << XO("These are our support methods:")
+         << wxT("</h2></center>")
+         << XO("We have several support methods:")
          << wxT("<p><ul><li>")
          /* i18n-hint: Preserve '[[help:Quick_Help|' as it's the name of a link.*/
          << XO("[[help:Quick_Help|Quick Help]] - if not installed locally, [[https://manual.audacityteam.org/quick_help.html|view online]]")
          << wxT("</li><li>")
          << XO(
 /* i18n-hint: Preserve '[[help:Main_Page|' as it's the name of a link.*/
-" [[help:Main_Page|Manual]] - if not installed locally, [[https://manual.audacityteam.org/|view online]]")
+" [[help:Main_Page|Audacity Manual]] - if not installed locally, [[https://manual.audacityteam.org/|view online]]")
          << wxT("</li><li>")
          << XO(
 " [[https://github.com/generic-pers0n/saucedacity/discussions|Discussions (on GitHub)]] - ask your question directly, online.")
          << wxT("</li></ul></p><p>")
          << wxT("<b>")
-         << XO("More:</b> Visit our [[https://github.com/generic-pers0n/saucedacity/wiki|Wiki]] for tips, tricks, extra tutorials and effects plug-ins.")
+         << XO("More:</b> Visit our [[https://github.com/saucedacity/saucedacity/wiki|Wiki]] for tips, tricks, extra tutorials and effects plug-ins.")
          << wxT("</p>")
 #endif
       ;

src/SplashDialog.cpp

@@ -53,14 +53,14 @@ most commonly asked questions about Audacity.
 
 SplashDialog * SplashDialog::pSelf=NULL;
 
-enum
+/*enum
 {
    DontShowID=1000,
-};
+};*/
 
 BEGIN_EVENT_TABLE(SplashDialog, wxDialogWrapper)
    EVT_BUTTON(wxID_OK, SplashDialog::OnOK)
-   EVT_CHECKBOX( DontShowID, SplashDialog::OnDontShow )
+//   EVT_CHECKBOX( DontShowID, SplashDialog::OnDontShow )
 END_EVENT_TABLE()
 
 IMPLEMENT_CLASS(SplashDialog, wxDialogWrapper)
@@ -158,16 +158,13 @@ void SplashDialog::Populate( ShuttleGui & S )
    S.Prop(1)
       .Position( wxEXPAND )
       .AddWindow( mpHtml );
-   S.Prop(0).StartMultiColumn(2, wxEXPAND);
-   S.SetStretchyCol( 1 );// Column 1 is stretchy...
    {
       S.SetBorder( 5 );
-      S.Id( DontShowID).AddCheckBox( XXO("Don't show this again at start up"), !bShow );
       S.SetBorder( 5 );
 
       S.Id(wxID_OK)
          .Prop(0)
-         .AddButton(XXO("OK"), wxALIGN_RIGHT| wxALL, true);
+         .AddButton(XXO("OK"), wxALIGN_RIGHT | wxALL, true);
    }
    S.EndVerticalLay();
 }
@@ -176,17 +173,11 @@ SplashDialog::~SplashDialog()
 {
 }
 
-void SplashDialog::OnDontShow( wxCommandEvent & Evt )
-{
-   bool bShow = !Evt.IsChecked();
-   gPrefs->Write(wxT("/GUI/ShowSplashScreen"), bShow );
-   gPrefs->Flush();
-}
-
 void SplashDialog::OnOK(wxCommandEvent & WXUNUSED(event))
 {
+   gPrefs->Write(wxT("/GUI/ShowSplashScreen"), false );
+   gPrefs->Flush();
    Show( false );
-
 }
 
 void SplashDialog::Show2( wxWindow * pParent )