Least stack-usage self-contained ftostr32np()

This is the optimal code for a self-contained formatter, although the
original code is crafty in being smaller and simpler, and can be
evaluated as using the original output as a scratch pad for state,
making the final formatter more straightforward. While this code is
longer, all code-paths are minimal.

Marlin/ultralcd.cpp

 
 //  convert float to space-padded string with -_23.4_ format
 char *ftostr32np(const float &x) {
-<<<<<<< HEAD
   long xx = abs(x * 100);
   uint8_t dig;
 
   dig = xx % 10;
   if (dig) { // 2 decimal places
     conv[5] = '0' + dig;
-    dig = (xx / 10) % 10;
-    conv[4] = '0' + dig;
+    conv[4] = '0' + (xx / 10) % 10;
     conv[3] = '.';
   }
   else { // 1 or 0 decimal place
   }
   conv[6] = '\0';
   return conv;
-=======
-  char *c = ftostr32(x);
-  if (c[0] == '0' || c[0] == '-') {
-    if (c[0] == '0') c[0] = ' ';
-    if (c[1] == '0') c[1] = ' ';
-  }
-  if (c[5] == '0') {
-    c[5] = ' ';
-    if (c[4] == '0') c[4] = c[3] = ' ';
-  }
-  return c;
->>>>>>> Patch to make Z look more like X and Y on UltraLCD
 }
 
 char *itostr31(const int &xx)