Fixed generation of configure header, now replacing date fields

with current date.
Added CMake script to generate a variable containing the current
date.
Removed last argument (the terminating NULL element) from output.

cmake/today.cmake

@@ -0,0 +1,16 @@
+# This script returns the current date in ISO format
+#
+# YYYY-MM-DD
+#
+MACRO (TODAY RESULT)
+    IF (WIN32)
+        EXECUTE_PROCESS(COMMAND "cmd" " /C date +%Y-%m-%d" OUTPUT_VARIABLE ${RESULT})
+        string(REGEX REPLACE "(..)/(..)/..(..).*" "\\1/\\2/\\3" ${RESULT} ${${RESULT}})
+    ELSEIF(UNIX)
+        EXECUTE_PROCESS(COMMAND "date" "+%Y-%m-%d" OUTPUT_VARIABLE ${RESULT})
+        string(REGEX REPLACE "(..)/(..)/..(..).*" "\\1/\\2/\\3" ${RESULT} ${${RESULT}})
+    ELSE (WIN32)
+        MESSAGE(SEND_ERROR "date not implemented")
+        SET(${RESULT} 000000)
+    ENDIF (WIN32)
+ENDMACRO (TODAY)