Add real manual pages

To some extent they duplicate the README but from a different angle.

CMakeLists.txt

@@ -191,19 +191,21 @@ install (DIRECTORY plugins/zyklonb/
 install (DIRECTORY plugins/degesch/
 	DESTINATION ${CMAKE_INSTALL_DATADIR}/degesch/plugins)
 
-# Generate documentation from program help
-find_program (HELP2MAN_EXECUTABLE help2man)
-if (NOT HELP2MAN_EXECUTABLE)
-	message (FATAL_ERROR "help2man not found")
+# Generate documentation from text markup
+find_program (ASCIIDOCTOR_EXECUTABLE asciidoctor)
+if (NOT ASCIIDOCTOR_EXECUTABLE)
+	message (FATAL_ERROR "asciidoctor not found")
 endif ()
 
 foreach (page zyklonb degesch kike)
 	set (page_output "${PROJECT_BINARY_DIR}/${page}.1")
 	list (APPEND project_MAN_PAGES "${page_output}")
 	add_custom_command (OUTPUT ${page_output}
-		COMMAND ${HELP2MAN_EXECUTABLE} -N
-			"${PROJECT_BINARY_DIR}/${page}" -o ${page_output}
-		DEPENDS ${page}
+		COMMAND ${ASCIIDOCTOR_EXECUTABLE} -b manpage
+			-a release-version=${project_version}
+			"${PROJECT_SOURCE_DIR}/${page}.adoc"
+			-o "${page_output}"
+		DEPENDS ${page}.adoc
 		COMMENT "Generating man page for ${page}" VERBATIM)
 endforeach ()