changed int to long to overcome overflow of number display

- related bug reports: Issue #201, Issue #213

Marlin/ultralcd.pde

@@ -2621,7 +2621,7 @@ char *ftostr31(const float &x)
 
 char *ftostr32(const float &x)
 {
-  int xx=x*100;
+  long xx=x*100;
   conv[0]=(xx>=0)?'+':'-';
   xx=abs(xx);
   conv[1]=(xx/100)%10+'0';
@@ -2666,7 +2666,7 @@ char *itostr4(const int &xx)
 //  convert float to string with +1234.5 format
 char *ftostr51(const float &x)
 {
-  int xx=x*10;
+  long xx=x*10;
   conv[0]=(xx>=0)?'+':'-';
   xx=abs(xx);
   conv[1]=(xx/10000)%10+'0';
@@ -2682,7 +2682,7 @@ char *ftostr51(const float &x)
 //  convert float to string with +123.45 format
 char *ftostr52(const float &x)
 {
-  int xx=x*100;
+  long xx=x*100;
   conv[0]=(xx>=0)?'+':'-';
   xx=abs(xx);
   conv[1]=(xx/10000)%10+'0';