adb: win32: initial IPv6 support and improved Winsock error reporting

Call getaddrinfo() for connecting to IPv6 destinations.

Winsock APIs do not set errno. WSAGetLastError() returns Winsock errors
that are more numerous than BSD sockets, so it really doesn't make sense
to map those to BSD socket errors. Plus, even if we did that, the
Windows C Runtime (that mingw binaries use) has a strerror() that does
not recognize BSD socket error codes.

The solution is to wrap the various libcutils socket_* APIs with
sysdeps.h network_* APIs. For POSIX, the network_* APIs just call
strerror(). For Windows, they call SystemErrorCodeToString() (adapted
from Chromium).

Also in this change:

 - Various other code was modified to return errors in a std::string*
   argument, to be able to surface the error string to the end-user.

 - Improved error checking and use of D() to log Winsock errors for
   improved debuggability.

 - For sysdeps_win32.cpp, added unique_fh class that works like
   std::unique_ptr, for calling _fh_close().

 - Fix win32 adb_socketpair() setting of errno in error case.

 - Improve _socket_set_errno() D() logging to reduce confusion. Map
   a few extra error codes.

 - Move adb_shutdown() lower in sysdeps_win32.cpp so it can call
   _socket_set_errno().

 - Move network_connect() from adb_utils.cpp to sysdeps.h.

 - Merge socket_loopback_server() and socket_inaddr_any_server() into
   _network_server() since most of the code was identical.

Change-Id: I945f36870f320578b3a11ba093852ba6f7b93400
Signed-off-by: Spencer Low <CompareAndSwap@gmail.com>
13 files changed