Issue 187 enable skipped ztest suites (#189)

* Fix some ztests that were skipped

* Expose bacapp_same_value()

* Fix bacapp, ptransfer tests

* Fix bugs in Load_Control object & tests

* refactor days functions from datetime module

* fix legacy ctests

* Add bacnet/basic/sys/days.[ch] to Zephyr build

* Update ztest to match from Zephyr v2.6.0; update ringbuf, datetime to build

* Fixup ztest test for object/acc

* Fix bvlc_address_from_ascii; enable/fix bvlc test

* Comment cleanup

* test/bacnet/basic/object/lc partially enabled

* Fix bacapp_decode_data_len return status on erroneous input

* fix ztest include fatal error

* fix ztest strsignal reference fatal error

* fix zassert_mem_equal reference syntax error

* fix zassert_mem_equal reference syntax error

Co-authored-by: Gregory Shue <gregory.shue@legrand.us>
Co-authored-by: Steve Karg <skarg@users.sourceforge.net>

src/bacnet/basic/sys/days.h

@@ -0,0 +1,58 @@
+/**
+ * @file
+ * @author Steve Karg <skarg@users.sourceforge.net>
+ * @date 1997
+ * @brief This file contains the function prototypes for the days calculations
+ */
+#ifndef DAYS_H
+#define DAYS_H
+#include <stdint.h>
+#include <stdbool.h>
+#include "bacnet/bacnet_stack_exports.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif /* __cplusplus */
+
+BACNET_STACK_EXPORT
+bool days_is_leap_year(uint16_t year);
+BACNET_STACK_EXPORT
+uint8_t days_per_month(uint16_t year, uint8_t month);
+BACNET_STACK_EXPORT
+uint32_t days_per_year(uint16_t year);
+BACNET_STACK_EXPORT
+uint16_t days_of_year(uint16_t year, uint8_t month, uint8_t day);
+BACNET_STACK_EXPORT
+uint16_t days_of_year_remaining(uint16_t year, uint8_t month, uint8_t day);
+BACNET_STACK_EXPORT
+void days_of_year_to_month_day(
+    uint32_t days, uint16_t year, uint8_t *pMonth, uint8_t *pDay);
+BACNET_STACK_EXPORT
+uint32_t days_apart(uint16_t year1,
+    uint8_t month1,
+    uint8_t day1,
+    uint16_t year2,
+    uint8_t month2,
+    uint8_t day2);
+BACNET_STACK_EXPORT
+uint32_t days_since_epoch(uint16_t epoch_year,
+    uint16_t year,
+    uint8_t month,
+    uint8_t day);
+BACNET_STACK_EXPORT
+void days_since_epoch_to_date(
+    uint16_t epoch_year,
+    uint32_t days,
+    uint16_t * pYear,
+    uint8_t * pMonth,
+    uint8_t * pDay);
+
+BACNET_STACK_EXPORT
+bool days_date_is_valid(uint16_t year,
+    uint8_t month,
+    uint8_t day);
+
+#ifdef __cplusplus
+}
+#endif /* __cplusplus */
+#endif