Buildsystem: Generate revision.h additionally during initial cmake run, also fixes displaying revision during run

--HG--
branch : trunk

CMakeLists.txt

@@ -57,6 +57,9 @@ if( UNIX )
   find_package(BZip2)
 endif()
 
+# Find revision ID and hash of the sourcetree
+include(cmake/genrev.cmake)
+
 # print out the results before continuing
 include(cmake/showoptions.cmake)