Migrating the remaining effects

This brings the builtin, LV2, and VAMP effects inline with the
Audio Units, LADSPA, and VST effects.  All effects now share
a common UI.

This gives all effects (though not implemented for all):

User and factory preset capability
Preset import/export capability
Shared or private configuration options

Builtin effects can now be migrated to RTP, depending on algorithm.
LV2 effects now support graphical interfaces if the plugin supplies one.
Nyquist prompt enhanced to provide some features of the Nyquist Workbench.

It may not look like it, but this was a LOT of work, so trust me, there
WILL be problems and everything effect related should be suspect.  Keep
a sharp eye (or two) open.

src/Audacity.h

@@ -152,22 +152,6 @@ void QuitAudacity();
    #endif
 #endif
 
-// For compilers that support precompilation, includes "wx/wx.h".
-// Mainly for MSVC developers.
-//
-// This precompilation is only done for non-unicode debug builds.
-// The rationale is that this is where there is the big time saving
-// because that's what you build whilst debugging.
-// Whilst disabling precompilation for other builds will ensure
-// that missing headers that would affect other platforms do get
-// seen by MSVC developers too.
-
-#ifndef UNICODE
-#ifdef __WXDEBUG__
-//#include <wx/wxprec.h>
-#endif
-#endif
-
 // This macro is used widely, so declared here.
 #define QUANTIZED_TIME(time, rate) ((double)((sampleCount)floor(((double)(time) * (rate)) + 0.5))) / (rate)