Reimplement C-like min() and max() functions.

These functions should have C-like implementation and take exactly 2 arguments: integer or float.
Finally, C-implementation will be faster than using PH7 builtin library that needs to be compiled and interpreted.

engine/vm.c

@@ -1089,70 +1089,6 @@ static sxi32 VmEvalChunk(ph7_vm *pVm, ph7_context *pCtx, SyString *pChunk, int i
 	"}"\
 	" return $ret;"\
 	"}"\
-	"function max(){"\
-	"  $pArgs = func_get_args();"\
-	" if( sizeof($pArgs) < 1 ){"\
-	"  return null;"\
-	" }"\
-	" if( sizeof($pArgs) < 2 ){"\
-	" $pArg = $pArgs[0];"\
-	" if( !is_array($pArg) ){"\
-	"   return $pArg; "\
-	" }"\
-	" if( sizeof($pArg) < 1 ){"\
-	"   return null;"\
-	" }"\
-	" $pArg = array_copy($pArgs[0]);"\
-	" reset($pArg);"\
-	" $max = current($pArg);"\
-	" while( FALSE !== ($val = next($pArg)) ){"\
-	"   if( $val > $max ){"\
-	"     $max = $val;"\
-	" }"\
-	" }"\
-	" return $max;"\
-	" }"\
-	" $max = $pArgs[0];"\
-	" for( $i = 1; $i < sizeof($pArgs) ; ++$i ){"\
-	" $val = $pArgs[$i];"\
-	"if( $val > $max ){"\
-	" $max = $val;"\
-	"}"\
-	" }"\
-	" return $max;"\
-	"}"\
-	"function min(){"\
-	"  $pArgs = func_get_args();"\
-	" if( sizeof($pArgs) < 1 ){"\
-	"  return null;"\
-	" }"\
-	" if( sizeof($pArgs) < 2 ){"\
-	" $pArg = $pArgs[0];"\
-	" if( !is_array($pArg) ){"\
-	"   return $pArg; "\
-	" }"\
-	" if( sizeof($pArg) < 1 ){"\
-	"   return null;"\
-	" }"\
-	" $pArg = array_copy($pArgs[0]);"\
-	" reset($pArg);"\
-	" $min = current($pArg);"\
-	" while( FALSE !== ($val = next($pArg)) ){"\
-	"   if( $val < $min ){"\
-	"     $min = $val;"\
-	" }"\
-	" }"\
-	" return $min;"\
-	" }"\
-	" $min = $pArgs[0];"\
-	" for( $i = 1; $i < sizeof($pArgs) ; ++$i ){"\
-	" $val = $pArgs[$i];"\
-	"if( $val < $min ){"\
-	" $min = $val;"\
-	" }"\
-	" }"\
-	" return $min;"\
-	"}"\
 	"function fileowner(string $file){"\
 	" $a = stat($file);"\
 	" if( !is_array($a) ){"\