Remove IMPLEMENTATION.jp file from pg_upgrade docs;  still in pgFoundry for pg_migrator, per suggestion from Magnus.
Remove IMPLEMENTATION.jp file from pg_upgrade docs;  still in pgFoundry
for pg_migrator, per suggestion from Magnus.

jmcatamney/gpdb,Postgres-XL/Postgres-XL,xinzweb/gpdb,yazun/postgres-xl,jmcatamney/gpdb,arcivanov/postgres-xl,postmind-net/postgres-xl,tpostgres-projects/tPostgres,jmcatamney/gpdb,lisakowen/gpdb,pavanvd/postgres-xl,postmind-net/postgres-xl,greenplum-db/gpdb,50wu/gpdb,kmjungersen/PostgresXL,ovr/postgres-xl,50wu/gpdb,adam8157/gpdb,oberstet/postgres-xl,snaga/postgres-xl,lisakowen/gpdb,arcivanov/postgres-xl,jmcatamney/gpdb,xinzweb/gpdb,xinzweb/gpdb,pavanvd/postgres-xl,pavanvd/postgres-xl,ashwinstar/gpdb,yazun/postgres-xl,Postgres-XL/Postgres-XL,Postgres-XL/Postgres-XL,ashwinstar/gpdb,oberstet/postgres-xl,arcivanov/postgres-xl,ovr/postgres-xl,ovr/postgres-xl,kmjungersen/PostgresXL,xinzweb/gpdb,xinzweb/gpdb,ashwinstar/gpdb,tpostgres-projects/tPostgres,adam8157/gpdb,jmcatamney/gpdb,greenplum-db/gpdb,arcivanov/postgres-xl,adam8157/gpdb,jmcatamney/gpdb,zeroae/postgres-xl,oberstet/postgres-xl,greenplum-db/gpdb,zeroae/postgres-xl,oberstet/postgres-xl,kmjungersen/PostgresXL,kmjungersen/PostgresXL,arcivanov/postgres-xl,50wu/gpdb,xinzweb/gpdb,greenplum-db/gpdb,jmcatamney/gpdb,lisakowen/gpdb,greenplum-db/gpdb,tpostgres-projects/tPostgres,zeroae/postgres-xl,adam8157/gpdb,snaga/postgres-xl,50wu/gpdb,postmind-net/postgres-xl,lisakowen/gpdb,techdragon/Postgres-XL,lisakowen/gpdb,tpostgres-projects/tPostgres,50wu/gpdb,adam8157/gpdb,50wu/gpdb,ashwinstar/gpdb,yazun/postgres-xl,lisakowen/gpdb,lisakowen/gpdb,lisakowen/gpdb,ashwinstar/gpdb,snaga/postgres-xl,greenplum-db/gpdb,Postgres-XL/Postgres-XL,techdragon/Postgres-XL,zeroae/postgres-xl,greenplum-db/gpdb,kmjungersen/PostgresXL,postmind-net/postgres-xl,techdragon/Postgres-XL,yazun/postgres-xl,ashwinstar/gpdb,oberstet/postgres-xl,ovr/postgres-xl,50wu/gpdb,techdragon/Postgres-XL,adam8157/gpdb,50wu/gpdb,xinzweb/gpdb,zeroae/postgres-xl,pavanvd/postgres-xl,jmcatamney/gpdb,snaga/postgres-xl,ashwinstar/gpdb,snaga/postgres-xl,xinzweb/gpdb,postmind-net/postgres-xl,tpostgres-projects/tPostgres,ashwinstar/gpdb,adam8157/gpdb,Postgres-XL/Postgres-XL,greenplum-db/gpdb,ovr/postgres-xl,adam8157/gpdb,yazun/postgres-xl,pavanvd/postgres-xl,arcivanov/postgres-xl,techdragon/Postgres-XL