Add strtol to jerry-libc and make use of it in jerry-main (#1891)

As a side effect, refactor the variable types in
`print_unhandled_exception` to reduce the overuse of sized integer
types (generic `unsigned int` is better than `uint32_t` if there is
no actual requirement on integer width).

JerryScript-DCO-1.0-Signed-off-by: Akos Kiss akiss@inf.u-szeged.hu

jerry-libc/include/stdlib.h

@@ -33,6 +33,7 @@ void __attribute__ ((noreturn)) exit (int);
 void __attribute__ ((noreturn)) abort (void);
 int rand (void);
 void srand (unsigned int);
+long int strtol (const char *, char **, int);
 
 #ifdef __cplusplus
 }