Feature/color objects color command (#302)

* added BACnetColorCommand and BACnetxyColor encoding and unit testing

* Added Color object and unit testing.

* Added Color Temperature object and Unit test

* Fix BVLC unit test warning.

* add port Makefile for extra types

* added RGB to and from CIE xy utility in sys folder, and add unit tests.

* added cmake-win32 target

* Change RP and RPM to use known property decoder.

Add color object RP and RPM decoding and printing
Fix RPM print for new reserved range above 4194303
Change default protocol-revision to 24 for Color object

* Integrate Color and Color Temperature objects into demo apps

Co-authored-by: Steve Karg <skarg@users.sourceforge.net>

ports/bdk-atxx4-mstp/Makefile

@@ -127,6 +127,7 @@ CORESRC =  \
 	$(BACNET_CORE)/bacint.c \
 	$(BACNET_CORE)/bacreal.c \
 	$(BACNET_CORE)/bacstr.c \
+	$(BACNET_CORE)/datetime.c \
 	$(BACNET_CORE)/dcc.c \
 	$(BACNET_CORE)/iam.c \
 	$(BACNET_CORE)/ihave.c \
@@ -237,6 +238,7 @@ CFLAGS += -fshort-enums
 CFLAGS += -Wall
 CFLAGS += -Wstrict-prototypes
 CFLAGS += -Wmissing-prototypes
+CFLAGS += -Wno-char-subscripts
 # put it all together
 CFLAGS += -gdwarf-2 $(BFLAGS) $(OPTIMIZATION)
 CFLAGS += -MD -MP -MT $(*F).o -MF dep/$(@F).d