Added a simplified ascii_to_int() implementation.

Removed dependency on hard-coded pager id. Pager id is now passed
as an environment string `pagerid' to tasks. Alternatively, this
could take space in the utcb of each task.

conts/libc/include/atoi.h

@@ -0,0 +1,26 @@
+#ifndef __ATOI_H__
+#define __ATOI_H__
+
+static inline int power(int exp, int mul)
+{
+	int total = 1;
+
+	while (exp > 0) {
+		total *= mul;
+		exp--;
+	}
+	return total;
+}
+
+static inline int atoi(char *str)
+{
+	int size = strlen(str);
+	int iter = size - 1;
+	int num = 0;
+
+	for (int i = 0; i < size; i++)
+		num += ((int)str[iter - i] - 48) * power(i, 10);
+	return num;
+}
+
+#endif