Add variable for animated fan, add float conversion w/o sign

A new variable was introduced to allow fan animation on the GLCD.
Add additional float to string conversion routine without sign
character. This is used for the coordinates visualisation on the GLCD.

Marlin/ultralcd.cpp

   return conv;
 }
 
+//  convert float to string with 123.4 format
+char *ftostr31ns(const float &x)
+{
+  int xx=x*10;
+  //conv[0]=(xx>=0)?'+':'-';
+  xx=abs(xx);
+  conv[0]=(xx/1000)%10+'0';
+  conv[1]=(xx/100)%10+'0';
+  conv[2]=(xx/10)%10+'0';
+  conv[3]='.';
+  conv[4]=(xx)%10+'0';
+  conv[5]=0;
+  return conv;
+}
+
 char *ftostr32(const float &x)
 {
   long xx=x*100;

Marlin/ultralcd.h

   void lcd_setstatuspgm(const char* message);
   void lcd_setalertstatuspgm(const char* message);
   void lcd_reset_alert_level();
+  
+  static unsigned char blink = 0;	// Variable for visualisation of fan rotation in GLCD
 
   #define LCD_MESSAGEPGM(x) lcd_setstatuspgm(PSTR(x))
   #define LCD_ALERTMESSAGEPGM(x) lcd_setalertstatuspgm(PSTR(x))
 char *itostr4(const int &xx);
 
 char *ftostr3(const float &x);
+char *ftostr31ns(const float &x); // float to string without sign character
 char *ftostr31(const float &x);
 char *ftostr32(const float &x);
 char *ftostr5(const float &x);