Starting directory auto, to receive auto-generated code.

Works for man page.

Doc/man/CMakeLists.txt

+set(AUTODIR "${CMAKE_SOURCE_DIR}/auto/Doc/man")
+file(MAKE_DIRECTORY ${AUTODIR})
+
 add_custom_target(
     man ALL
-    DEPENDS bornagain.1
+    DEPENDS "${AUTODIR}/bornagain.1"
 )
 
 add_custom_command(
-    OUTPUT bornagain.1
-    COMMAND pod2man -s 1 -c "BornAgain manual" ${CMAKE_CURRENT_SOURCE_DIR}/bornagain.pod ${CMAKE_CURRENT_BINARY_DIR}/bornagain.1
+    OUTPUT "${AUTODIR}/bornagain.1"
+    COMMAND pod2man -s 1 -c "BornAgain manual" ${CMAKE_CURRENT_SOURCE_DIR}/bornagain.pod ${AUTODIR}/bornagain.1
     DEPENDS bornagain.pod
 )
 
-install(FILES ${CMAKE_CURRENT_BINARY_DIR}/bornagain.1 DESTINATION ${CMAKE_INSTALL_PREFIX}/man/man1)
+install(FILES ${AUTODIR}/bornagain.1 DESTINATION ${CMAKE_INSTALL_PREFIX}/man/man1)

auto/README

+This directory, auto, contains files that are automatically
+generated by tools other than CMake, Make, and the compiler.
+
+They are distributed as part of the source archive, but they
+are not included in the git repository [TODO: DISCUSS THIS].
+
+A user, who just wants to compile BornAgain, should consider
+the contents of this directory as part of the source, period.
+
+A developer, on the other hand, will sooner or later need
+to regenerate some or all sources contained in this directory.
+For this, use the command top-level cmake command with
+option -DREGENERATE [TODO: UPDATE THIS].
+
+Contents of this directory:
+
+Doc/man:
+  Unix man page in troff format, generated by pod2man.