Changes to the Effect dialog based on QA suggestions

Solves the problem of what the "Settings" button should say
by converting it to a bitmap button.

Adds the missing "bypass effect" button.

The Ok/Cancel buttons are now Apply/Close buttons and the
dialog stays open after the apply is done.

Record is no longer disabled when an RTP effect is open as
the RTP effect now monitors when recording starts and disables
its buttons as needed.

Added "Play", "Skip forward", and "Skip backward" buttons.
While the other stuff is required, this last one is in to
get a feel for its usefulness.  We'll need to get feedback
on it pretty quickly so we can rip it out if need be.

src/ShuttleGui.h

@@ -337,6 +337,7 @@ enum
    eSettingsButton= 0x0080,
    ePreviewDryButton  = 0x0100,
    eApplyButton   = 0x0200,
+   eCloseButton   = 0x0400,
 };
 
 enum
@@ -344,12 +345,13 @@ enum
    ePreviewID     = wxID_LOWEST - 1,
    eDebugID       = wxID_LOWEST - 2,
    eSettingsID    = wxID_LOWEST - 3,
-   ePreviewDryID  = wxID_LOWEST - 4
+   ePreviewDryID  = wxID_LOWEST - 4,
+   eCloseID       = wxID_CANCEL
 };
 
 AUDACITY_DLL_API wxSizer *CreateStdButtonSizer( wxWindow *parent,
                                long buttons = eOkButton | eCancelButton,
-                               wxButton *extra = NULL );
+                               wxWindow *extra = NULL );
 
 // ShuttleGui extends ShuttleGuiBase with Audacity specific extensions.
 class AUDACITY_DLL_API ShuttleGui : public ShuttleGuiBase