Remove the built-in print and the jerry_port_console port API functions (#1749)

The built-in `print` is removed from jerry-core, but an external
`print` implementation is added to jerry-main. From now on, all
embedders of the engine have to implement their own `print` if they
need such a functionality.

For printing results in REPL mode of jerry-main, the external
`print` handler is called directly instead of looking up the `print`
function registered into the global object. (The two are the same,
but the indirection is not needed anymore.)

Because jerry-core does not contain `print` anymore,
`jerry_port_console` is removed from the port API. The default port
is updated, i.e., the implementation of `jerry_port_console` is
removed. Additionally, all references to `jerry_port_console` in
jerry-main are replaced by `printf`.

Speculatively, `jerry_port_console` is also removed from all
non-default targets. Most targets implemented it for the sake of the
engine only; in those targets the removal was trivial. Where the
function was called from the embedder application as well, the
calls were replaced with equivalents (e.g., `printf`, `printk`).

NOTE 1: This is a breaking change!

NOTE 2: This patch still leaves several targets without a JS `print`
implementation.

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

tests/unit-core/test-api.c

@@ -356,9 +356,6 @@ main (void)
   double number_val;
   char buffer[32];
 
-  is_ok = test_run_simple ("print ('Hello, World!');");
-  TEST_ASSERT (is_ok);
-
   is_ok = test_run_simple ("throw 'Hello World';");
   TEST_ASSERT (!is_ok);