Fix (most) compilation warnings in Intel C++ Compiler (#38)

* Use BACNET_OBJECT_TYPE for all object type variables.

* Fix ICC "mixing enumerated type" warnings for assignments and parameters.

* Network Port: Use enums for state structs and remove erroneous bounds checks copy-pasted from IP_Subnet_Prefix setter.

* Fix ICC "unreachable statement" warnings.

* Fix ICC "unused variable" warnings when printing is disabled.

* Fix ICC "mixing enumerated type" warnings for struct initializers { 0 } by ensuring the first member is an integer type.

* Send_GetEvent_Global: Return 0 (invalid TSM invoke ID) instead of -1 = 255 (technically valid invoke ID) on failure.

* Fix ICC "pointless comparison" warnings.

* Fix wrong import in objects.c (memset being used).

* Fix signedness warnings and inconsistencies. Include -1 = 255 check in cov_address_get().

* Add some guards for BACAPP_LIGHTING_COMMAND to avoid errors/warnings.

* RPM test fixes

* Address requested changes. (#38)

ports/pic18f97j60/device.c

@@ -194,7 +194,7 @@ unsigned Device_Object_List_Count(
 /* for discovery, it must be consistent! */
 bool Device_Object_List_Identifier(
     uint32_t array_index,
-    int *object_type,
+    BACNET_OBJECT_TYPE *object_type,
     uint32_t * instance)
 {
     bool status = false;
@@ -273,7 +273,7 @@ int Device_Read_Property_Local(
     BACNET_BIT_STRING bit_string;
     BACNET_CHARACTER_STRING char_string;
     uint32_t i = 0;
-    int object_type = 0;
+    BACNET_OBJECT_TYPE object_type = OBJECT_NONE;
     uint32_t instance = 0;
     uint32_t count = 0;
     BACNET_TIME local_time;