Bugfix/fix redundant compiler flags (#658)

* Improved GCC compiler flags in ARM, OS, and test builds. Removed redundant flags, and made them consistent across various builds.

* Fixed redundant redeclaration of various functions detected by change in compiler flags.

* Fixed string truncation warning in bip-init detected by change in compiler flags.

* Fixed some set-but-not-used variables by creating dummy functions instead of using macros.

src/bacnet/basic/object/client/device-client.c

@@ -102,8 +102,7 @@ static uint32_t Database_Revision = 0;
 /* Slave_Address_Binding */
 /* Profile_Name */
 
-/* local forward (semi-private) and external prototypes */
-int Device_Read_Property_Local(BACNET_READ_PROPERTY_DATA *rpdata);
+/* external prototypes */
 extern int Routed_Device_Read_Property_Local(BACNET_READ_PROPERTY_DATA *rpdata);
 extern bool Routed_Device_Write_Property_Local(
     BACNET_WRITE_PROPERTY_DATA *wp_data);