Generate the config header in the build directory.

  - Generating it in the source/include directory is conflicting with
    the autoconf build. They keep overwriting the same file.

    It should have been in the build folder from the begining anyway.
    It belongs there. Should not pollute the source dir as much as possible.

antlr/3.2/libantlr3c-3.2/CMakeLists.txt

@@ -27,11 +27,13 @@ include(CheckTypeSize)
 check_type_size(intptr_t INTPTR_T)
 
 # Generate a configure header
-configure_file(${CMAKE_CURRENT_SOURCE_DIR}/antlr3config.h.in.cmake ${CMAKE_CURRENT_SOURCE_DIR}/include/antlr3config.h)
+configure_file(${CMAKE_CURRENT_SOURCE_DIR}/antlr3config.h.in.cmake ${CMAKE_CURRENT_BINARY_DIR}/include/antlr3config.h)
 
 
 
 add_library(omantlr3 STATIC)
 
 target_sources(omantlr3 PRIVATE ${ANTLR_SOURCES})
 target_include_directories(omantlr3 PUBLIC ${CMAKE_CURRENT_SOURCE_DIR}/include)
+# The config header is generated in the build dir.
+target_include_directories(omantlr3 PUBLIC ${CMAKE_CURRENT_BINARY_DIR}/include)