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/stm32f4xx/Makefile

@@ -59,6 +59,7 @@ BACNET_SRC = \
 	$(BACNET_CORE)/bacreal.c \
 	$(BACNET_CORE)/bacstr.c \
 	$(BACNET_CORE)/datalink/crc.c \
+	$(BACNET_CORE)/datetime.c \
 	$(BACNET_CORE)/dcc.c \
 	$(BACNET_CORE)/iam.c \
 	$(BACNET_CORE)/ihave.c \
@@ -71,6 +72,7 @@ BACNET_SRC = \
 	$(BACNET_CORE)/reject.c \
 	$(BACNET_CORE)/rp.c \
 	$(BACNET_CORE)/rpm.c \
+	$(BACNET_CORE)/timestamp.c \
 	$(BACNET_CORE)/whohas.c \
 	$(BACNET_CORE)/whois.c \
 	$(BACNET_CORE)/wp.c
@@ -155,6 +157,8 @@ CFLAGS += -Wall
 CFLAGS += -Wno-missing-braces
 # don't warn about missing prototypes since STM32 library doesn't have some
 CFLAGS += -Wno-missing-prototypes
+# don't warn about array subscript being char
+CFLAGS += -Wno-char-subscripts
 
 #  -Wa,<options> Pass comma-separated <options> on to the assembler
 AFLAGS = -Wa,-ahls,-mapcs-32,-adhlns=$(<:.s=.lst)