Now build "gpg" binary but install as "gpg2"

* configure.ac (USE_GPG2_HACK): New ac_define am_conditional.
* common/homedir.c (gnupg_module_name): Replace use of macro
NAME_OF_INSTALLED_GPG.
* g10/keygen.c (generate_keypair): Ditto.
* g10/Makefile.am (bin_PROGRAMS): Remove.
(noinst_PROGRAMS): Add gpg or gpg2 and gpgv or gpg2.
(gpg2_hack_list): New.
(use_gpg2_hack): New.
(gpg2_SOURCES): Rename to gpg_SOURCES.
(gpgv2_SOURCES): Rename to gpgv_SOURCES.
(gpg2_LDADD): Rename to gpg_LDADD.
(gpgv2_LDADD): Rename to gpgv_LDADD.
(gpg2_LDFLAGS): Rename to gpg_LDFLAGS.
(gpgv2_LDFLAGS): Rename to gpgv2_LDFLAGS.
(install-exec-hook): Remove WinCE specific rules and add new rules.
(uninstall-local): Uninstall gpg/gpg2 and gpgv/gpgv2.
* tests/openpgp/Makefile.am (required_pgms): s/gpg2/gpg/.
* tests/openpgp/defs.inc: Ditto.
* tests/openpgp/gpgtar.test: Ditto.
* tests/openpgp/mkdemodirs: Ditto.
* tests/openpgp/signdemokey: Ditto.

* Makefile.am (DISTCHECK_CONFIGURE_FLAGS): Remove obsolete
--enable-mailto, add --enable-gpg2-is-gpg.
--

Although we need to duplicate some automake generated code this method
allows to easily switch the name of the installed target using the
configure option "--enable-gpg2-is-gpg".

Signed-off-by: Werner Koch <wk@gnupg.org>

tests/openpgp/defs.inc

@@ -215,7 +215,7 @@ fi
 unset GPG_AGENT_INFO
 
 # (--no-permission-warning makes only sense on the commandline)
-GPG="../../g10/gpg2 --no-permission-warning "
+GPG="../../g10/gpg --no-permission-warning "
 # (We may not use a relative name for gpg-agent.)
 GPG_AGENT="$(cd ../../agent && /bin/pwd)/gpg-agent"
 GPG_CONNECT_AGENT="../../tools/gpg-connect-agent"