Add extra version information to avrdude output

Some downstream projects build avrdude and want to add
their own version information to the avrdude version.

This adds a clean way to do that without patching for both
cmake and automake based builds:

    cmake -DEXTRA_VERSION:STRING=-arduino.1-rc1
    ../configure EXTRA_VERSION=-arduino.1-rc1

After building avrdude, the last line of "avrdude -?"
will now look similar to the following, depending on
whether you are building an avrdude git checkout or
an avrdude release:

    avrdude version 8.0-20240901-arduino.1-rc1 (30e19f2), https://github.com/avrdudes/avrdude
    avrdude version 8.1-arduino.1-rc1 (30e19f2), https://github.com/avrdudes/avrdude

CMakeLists.txt

@@ -49,7 +49,7 @@ include(FindPackageMessage)
 include(GNUInstallDirs)
 
 set(CONFIG_DIR "${CMAKE_INSTALL_FULL_SYSCONFDIR}")
-set(AVRDUDE_FULL_VERSION ${CMAKE_PROJECT_VERSION})
+set(AVRDUDE_FULL_VERSION "${CMAKE_PROJECT_VERSION}${EXTRA_VERSION}")
 
 # =====================================
 # Get Git commit info
@@ -91,7 +91,7 @@ if(Git_FOUND)
 
     # If the commit is not tagged, include the date and commit hash in the full version string.
     if(NOT GIT_COMMIT_HASH STREQUAL GIT_TAG_HASH)
-        set(AVRDUDE_FULL_VERSION "${CMAKE_PROJECT_VERSION}-${GIT_COMMIT_DATE} (${GIT_COMMIT_HASH})")
+        set(AVRDUDE_FULL_VERSION "${CMAKE_PROJECT_VERSION}-${GIT_COMMIT_DATE}${EXTRA_VERSION} (${GIT_COMMIT_HASH})")
     endif()
 endif()
 
@@ -374,6 +374,7 @@ if (DEBUG_CMAKE)
     message(STATUS "CMAKE_C_COMPILER: ${CMAKE_C_COMPILER}")
     message(STATUS "CONFIG_DIR: ${CONFIG_DIR}")
     message(STATUS "AVRDUDE_FULL_VERSION: ${AVRDUDE_FULL_VERSION}")
+    message(STATUS "EXTRA_VERSION: ${EXTRA_VERSION}")
     message(STATUS "USE_EXTERNAL_LIBS: ${USE_EXTERNAL_LIBS}")
     message(STATUS "USE_LIBUSBWIN32: ${USE_LIBUSBWIN32}")
     message(STATUS "HAVE_LIBELF: ${HAVE_LIBELF}")

src/configure.ac

@@ -80,11 +80,12 @@ AC_MSG_RESULT([$PACKAGE_VERSION])
 dnl Compose the full version message mirroring the cmake one, inform
 dnl about it and pass it on to avrdude.conf and the "avrdude -?"
 dnl version message
+AC_ARG_VAR([EXTRA_VERSION], [extra version information to be added to version info])
 AC_MSG_CHECKING([versioninfo derived AVRDUDE_FULL_VERSION])
 if test "x$GIT_COMMIT_HASH" = "x$GIT_TAG_HASH"; then
-	AVRDUDE_FULL_VERSION="$PACKAGE_VERSION"
+	AVRDUDE_FULL_VERSION="$PACKAGE_VERSION$EXTRA_VERSION"
 else
-	AVRDUDE_FULL_VERSION="$PACKAGE_VERSION ($GIT_COMMIT_HASH)"
+	AVRDUDE_FULL_VERSION="$PACKAGE_VERSION$EXTRA_VERSION ($GIT_COMMIT_HASH)"
 fi
 AC_MSG_RESULT([$AVRDUDE_FULL_VERSION])
 AC_DEFINE_UNQUOTED([AVRDUDE_FULL_VERSION], ["$AVRDUDE_FULL_VERSION"],