Bump version and update ChangeLog

Author: Chad Trabant

ChangeLog

@@ -1,3 +1,7 @@
+2017.075: 2.19.3
+	- Add missing public, global symbols to libmseed.map, thanks
+	to Elliott Sales de Andrade.
+
 2017.061: 2.19.2
 	- Provide install target in Makefile thanks to by Pierre Duperray.
 	- Deprecate dynamic build target, the shared target will now build

libmseed.h

@@ -28,8 +28,8 @@
 extern "C" {
 #endif
 
-#define LIBMSEED_VERSION "2.19.2"
-#define LIBMSEED_RELEASE "2017.061"
+#define LIBMSEED_VERSION "2.19.3"
+#define LIBMSEED_RELEASE "2017.075"
 
 /* C99 standard headers */
 #include <stdlib.h>