config CHANGE timeout step is configurable

Fixes #164
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 7e69082..3a72b83 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -60,6 +60,7 @@
 set(READ_INACTIVE_TIMEOUT 20 CACHE STRING "Maximum number of seconds waiting for new data once some data have arrived")
 set(READ_ACTIVE_TIMEOUT 300 CACHE STRING "Maximum number of seconds for receiving a full message")
 set(MAX_PSPOLL_THREAD_COUNT 6 CACHE STRING "Maximum number of threads that could simultaneously access a ps_poll structure")
+set(TIMEOUT_STEP 100 CACHE STRING "Number of microseconds tasks are repeated until timeout elapses")
 set(SCHEMAS_DIR "${CMAKE_INSTALL_PREFIX}/${DATA_INSTALL_DIR}" CACHE STRING "Directory with internal lnc2 schemas")
 
 if(ENABLE_DNSSEC AND NOT ENABLE_SSH)