Bump version

NEWS

+gcr 3.28.0:
+- Fix year 2038 workaround in ASN.1 decoder [#787963]
+- Fix test errors when ssh-keygen is not found
+- Updated translations
+
 gcr 3.27.92:
 - Provide API for reliably calling ssh programs [#735873]
 - Updated translations

configure.ac

 
 m4_define([gcr_major], [3])
-m4_define([gcr_minor], [27])
-m4_define([gcr_micro], [92])
+m4_define([gcr_minor], [28])
+m4_define([gcr_micro], [0])
 
 AC_PREREQ([2.63])
 AC_INIT([gcr], [gcr_major.gcr_minor.gcr_micro],