add some tests.

Before:
> {a: 1}
1
> (function() {
...   // foo
...   return 1;
... })();
...

Now:
> {a: 1}
{ a : 1 }
> (function() {
...   // foo
...   return 1;
... })();
1
>

Stub out new platform functions.

This reverts commit 24aded07.

Fixes GH-543

Prevents valgrind from complaining and still tests that buffer data is
treated as unsigned.

Both HexDecode and unbase64 allocate buffers, which weren't being freed.

AF_UNIX sockets can have a pathname, be unnamed, or abstract (Linux
only). If an unnamed socket is returned by getsockname, getpeername, or
accept, sun_path should not be inspected.

net:1100
        if (e.errno != EMFILE) throw e;
                               ^
Error: ECONNABORTED, Software caused connection abort
    at IOWatcher.callback (net:1098:24)
    at node.js:773:9