Fixed deadlock bug when doing resize of key buffer while key buffer was in active use


myisam/mi_locking.c:
  Better fix for myisamchk --sort-index on windows
mysql-test/r/symlink.result:
  Update results
mysql-test/t/symlink.test:
  Update results
mysys/mf_keycache.c:
  Fixed deadlock bug when doing resize of key buffer while key buffer was in active use
sql/ha_myisam.cc:
  simple optimization
sql/sql_show.cc:
  Fixed theoretical buffer overrun
  Reset variable properly before calling update_create_info()