additional fixes for 64-bit
---
Merge mysql.com:/misc/mysql/31177/50-31177
into  mysql.com:/misc/mysql/31177/51-31177
---
Bug#31177: Server variables can't be set to their current values

additional 5.1 fixes (for plugins)


mysql-test/t/variables.test:
  replace 32-bit and 64-bit values
  ---
  manual merge
mysys/my_getopt.c:
  'mod' no longer used.
  on 64-bit, limit to (signed) (LONG)LONG_MAX to prevent badness
  in classes using longlong.
sql/sql_plugin.cc:
  handle signedness in plugin-vars so we won't hit an assert()
  in getopt_*_limit_value()