Pick callbacks now take Fl_Gl_Window, not Fl_Plot/Fl_Gview, as first arg,

so we can use same function for both.

src/Gview.H

@@ -135,8 +135,8 @@ class Fl_Gview : public Fl_Gl_Window {
   int inpick() const { return inpick_; } // draw()ers: am I in GL_SELECT mode?
   void picksize( float width, float height );
   void pickbuffer( int words, GLuint *buf );
-  void picker( void (*pickcb)(Fl_Gview *, int, int, GLuint *, void *arg), void *arg ); 
-  void (*picker( void **argp = 0 ))(Fl_Gview *, int, int, GLuint *, void *arg);
+  void picker( void (*pickcb)(Fl_Gl_Window *, int, int, GLuint *, void *arg), void *arg ); 
+  void (*picker( void **argp = 0 ))(Fl_Gl_Window *, int, int, GLuint *, void *arg);
   int pickresults( int *wordsp, GLuint **bufp );  /* returns num hits, too */
   int do_pick( float pickx, float picky ); /* Calls back function given by picker() */
 
@@ -208,7 +208,7 @@ class Fl_Gview : public Fl_Gl_Window {
   int target_;
   int movingtarget_;
 
-  void (*pickcb_)( Fl_Gview *, int hits, int nents, GLuint *buf, void *arg );
+  void (*pickcb_)( Fl_Gl_Window *, int hits, int nents, GLuint *buf, void *arg );
   int inpick_;
   float pickx_, picky_, pickwidth_, pickheight_;
   int picknents_, pickhits_;

src/Plot.H

@@ -52,8 +52,8 @@ class Fl_Plot : public Fl_Gl_Window {
   int inpick() const { return inpick_; } // draw()ers: am I in GL_SELECT mode?
   void picksize( float width, float height );
   void pickbuffer( int words, GLuint *buf );
-  void picker( void (*pickcb)(Fl_Plot *, int, int, GLuint *, void *arg), void *arg ); 
-  void (*picker( void **argp = 0 ))(Fl_Plot *, int, int, GLuint *, void *arg);
+  void picker( void (*pickcb)(Fl_Gl_Window *, int, int, GLuint *, void *arg), void *arg ); 
+  void (*picker( void **argp = 0 ))(Fl_Gl_Window *, int, int, GLuint *, void *arg);
   int pickresults( int *wordsp, GLuint **bufp );  /* returns num hits, too */
   int do_pick( float pickx, float picky ); /* Calls back function given by picker() */
 
@@ -76,7 +76,7 @@ class Fl_Plot : public Fl_Gl_Window {
   float x0_, x1_, y0_, y1_;
   char *xtitle_, *ytitle_;
 
-  void (*pickcb_)( Fl_Plot *, int hits, int nents, GLuint *buf, void *arg );
+  void (*pickcb_)( Fl_Gl_Window *, int hits, int nents, GLuint *buf, void *arg );
   int inpick_;
   float pickx_, picky_, pickwidth_, pickheight_;
   int picknents_, pickhits_;