Update NEWS to 6.1.3

NEWS

+libdvdread (6.1.3)
+ * Improvements for OpenBSD
+ * Fix crashes on some DVD (0 PCGI SRP)
+ * Misc source fixes and cleanups, including fixes for recent toolchains
+
 libdvdread (6.1.2)
  * Fix Win32 Unicode paths opening
  * Fix warnings and build improvements

configure.ac

 dnl library version number
 m4_define([dvdread_major], 6)
 m4_define([dvdread_minor], 1)
-m4_define([dvdread_micro], 2)
+m4_define([dvdread_micro], 3)
 m4_define([dvdread_version],[dvdread_major.dvdread_minor.dvdread_micro])
 
 AC_INIT(libdvdread, dvdread_version)