Added gpgme autoconf m4 macro to fix an undefined AM_PATH_GPGME error

For systems that don't have libgpgme installed, the addition of the m4/gpgme.m4
file fixes the following error when running the autogen.sh script:

configure.ac:313: error: possibly undefined macro: AC_DEFINE
      If this token and others are legitimate, please use m4_pattern_allow.
      See the Autoconf documentation.
configure.ac:326: error: possibly undefined macro: AM_PATH_GPGME
configure.ac:329: error: possibly undefined macro: AC_MSG_FAILURE
Merge branch 'master' into gpgme_autoconf_macro
added m4/gpgme.m4 file
Added backwards compatibility section to the client man page

Added backwards compatibility section and new material on a 'quick start'
subsection for the EXAMPLES section.
Updated copyright dates, removed NEWS file in favor of the ChangeLog
restored the NEWS file since autoconf seems to need it
started on libfko.texi function prototype and FKO error code documentation updates
[test suite] added backwards compatibility test for truncated keys longer > 16 chars
[test suite] minor bug fix to include the new legacy long key file in Makefile.am
Merge remote-tracking branch 'fjoncourt/master'

Closes #74 - allows a passphrase to be read from STDIN or from a file descriptor
via --fd.
fko-wrapper update to print fko_errstr() text, and to have one successful HMAC cycle
a few HMAC doc updates to the libfko.texi file
Merge branch 'gpgme_autoconf_macro'

This commit adds a new m4/gpgme.m4 to allow autogen.sh to work properly when
libgpgme is not installed.  Closes #72.
Merge remote-tracking branch 'upstream/master'

Conflicts:
	client/fwknop.8.in