Feature/bacnet discover dnet devices (#583)

* Added an example application to discover devices and their objects and properties on a specific destination network. The application uses a BACnet Discovery FSM module along with the BACnet R/W FSM.  The BACnet Discovery module stores the binary property data in Keylists and includes device object property queries and iterators.

* Added callback from BACnet R/W FSM module for I-Am messages.

* Removed dependency in BACnet R/W FSM module on rpm_ack_decode_service_request() which uses calloc/free value lists.  Created an alternate RPM-ACK to RP-ACK processing function.

* Changed RPM handler to skip over unknown property values

CMakeLists.txt

@@ -34,6 +34,11 @@ option(
   "compile the bacpoll app"
   ON)
 
+  option(
+    BACNET_BUILD_BACDISCOVER_APP
+    "compile the bacdiscover app"
+    ON)
+
 option(
   BACDL_ETHERNET
   "compile with ethernet support"
@@ -70,6 +75,18 @@ if(NOT CMAKE_BUILD_TYPE)
   set(CMAKE_BUILD_TYPE Release)
 endif()
 
+# Build types
+if ("${CMAKE_BUILD_TYPE}" STREQUAL "Release")
+    message(STATUS "Maximum optimization for speed")
+elseif ("${CMAKE_BUILD_TYPE}" STREQUAL "RelWithDebInfo")
+    message(STATUS "Maximum optimization for speed, debug info included")
+elseif ("${CMAKE_BUILD_TYPE}" STREQUAL "MinSizeRel")
+    message(STATUS "Maximum optimization for size")
+else ()
+    message(STATUS "Minimal optimization, debug info included")
+    add_compile_definitions(DEBUG_ENABLED=1)
+endif ()
+
 option(
   BACNET_STACK_DEPRECATED_DISABLE 
   "Disable deprecation compile warnings" 
@@ -671,6 +688,14 @@ if(BACNET_STACK_BUILD_APPS)
     target_link_libraries(bacpoll PRIVATE ${PROJECT_NAME})
   endif(BACNET_BUILD_BACPOLL_APP)
 
+  if(BACNET_BUILD_BACDISCOVER_APP)
+  add_executable(bacdiscover
+        apps/server-discover/main.c
+        src/bacnet/basic/client/bac-discover.c
+        src/bacnet/basic/client/bac-rw.c)
+  target_link_libraries(bacdiscover PRIVATE ${PROJECT_NAME})
+  endif(BACNET_BUILD_BACDISCOVER_APP)
+
   if(NOT BACDL_ETHERNET)
     add_executable(readbdt apps/readbdt/main.c)
     target_link_libraries(readbdt PRIVATE ${PROJECT_NAME})