Log Message:
Update to 2.4.2

Changelog:
Noteworthy changes in version 2.4.2 (2015-12-02) [C7/A7/R2]
------------------------------------------------

 * The nPth version of the connect system hook does now wrap the call
   with npth_unprotec/npth_protect to avoid blocking during a connect.

 * Add feature to assuan_sock_connect_byname to test for SOCKS5
   availability.

Noteworthy changes in version 2.4.1 (2015-11-23) [C7/A7/R1]
------------------------------------------------

 * In Tor mode fallback to port 9150 if 9050 is not listening.

 * Allow building with older mingw-w64 versions.

Noteworthy changes in version 2.4.0 (2015-11-03) [C7/A7/R0]
------------------------------------------------

 * New flags "socks" and "tor-mode" for \ 
assuan_sock_{set,get}_flag.

 * New function assuan_sock_connect_byname.

 * Require at least libgpg-error 1.17.

 * Interface changes relative to the 2.3.0 release:
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 assuan_sock_connect_byname    NEW.
 ASSUAN_SOCK_TOR               NEW.
 ASSUAN_SOCK_SOCKS             NEW.
 assuan_sock_set_flag          EXTENDED.
 assuan_sock_get_flag          EXTENDED.

Noteworthy changes in version 2.3.0 (2015-08-28) [C6/A6/R0]
------------------------------------------------

 * Now wipes out the memory of the context structure before freeing.
   The context may have stored sensitive data in its line buffers.

 * Fixed a problem with the data length limit in assuan_inquire.

 * Returns GPG_ERR_SOURCE_ASSUAN with errors from functions w/o a
   context.

 * Two new functions to tweak the behaviour of the socket wrappers.

 * Experimental code to support Cygwin's local sockets.

 * By default build without a build timestamp.

 * Interface changes relative to the 2.2.1 release:
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 assuan_sock_set_flag     NEW.
 assuan_sock_get_flag     NEW.