ICU 56 step 4: Apply post-56 fixes for measure/date format

patches/tzdetect2.patch

-diff --git a/source/common/putil.cpp b/source/common/putil.cpp
-index 599dad9..0f5090c 100644
---- a/source/common/putil.cpp
-+++ b/source/common/putil.cpp
-@@ -970,6 +970,15 @@ static char* searchForTZFile(const char* path, DefaultTZInfo* tzInfo) {
-     return result;
- }
- #endif
-+
-+U_CAPI void U_EXPORT2
-+uprv_tzname_clear_cache()
-+{
-+#if defined(CHECK_LOCALTIME_LINK) && !defined(DEBUG_SKIP_LOCALTIME_LINK)
-+    gTimeZoneBufferPtr = NULL;
-+#endif
-+}
-+
- U_CAPI const char* U_EXPORT2
- uprv_tzname(int n)
- {
-diff --git a/source/common/putilimp.h b/source/common/putilimp.h
-index d2c1c66..e3da340 100644
---- a/source/common/putilimp.h
-+++ b/source/common/putilimp.h
-@@ -483,6 +483,12 @@ U_INTERNAL int32_t  U_EXPORT2 uprv_timezone(void);
- U_INTERNAL const char* U_EXPORT2 uprv_tzname(int n);
- 
- /**
-+ * Reset the global tzname cache.
-+ * @internal
-+ */
-+U_INTERNAL void uprv_tzname_clear_cache();
-+
-+/**
-  * Get UTC (GMT) time measured in milliseconds since 0:00 on 1/1/1970.
-  * This function is affected by 'faketime' and should be the bottleneck for all user-visible ICU time functions.
-  * @return the UTC time measured in milliseconds
-diff --git a/source/i18n/timezone.cpp b/source/i18n/timezone.cpp
-index 6b3f8d2..a80fdda 100644
---- a/source/i18n/timezone.cpp
-+++ b/source/i18n/timezone.cpp
-@@ -453,6 +453,8 @@ TimeZone::detectHostTimeZone()
- 
-     uprv_tzset(); // Initialize tz... system data
- 
-+    uprv_tzname_clear_cache();
-+
-     // Get the timezone ID from the host.  This function should do
-     // any required host-specific remapping; e.g., on Windows this
-     // function maps the Date and Time control panel setting to an