performance version in MySQL Version name created too long file names

for files in tar command as part of make of a source distribution.
Only 99 characters are supported. Abbreviated performance version
by pv thus. Should be ok since shorter than ndb, and if MySQL Cluster
Carrier Grade Edition has thus 1 character longer version names.

configure.in

@@ -10,7 +10,7 @@ AC_CANONICAL_SYSTEM
 #
 # When changing major version number please also check switch statement
 # in mysqlbinlog::check_master_version().
-AM_INIT_AUTOMAKE(mysql, 5.1.31-performance-version-0.2.0)
+AM_INIT_AUTOMAKE(mysql, 5.1.31-pv-0.2.0)
 AM_CONFIG_HEADER([include/config.h:config.h.in])
 
 PROTOCOL_VERSION=10