Fix wrong cast of time()

include/my_pthread.h:
  Safety fix that also removes compiler warnings
sql/handler.h:
  Changed timestamp columns to be of type time_t
storage/maria/ma_check.c:
  Removed wrong cast
storage/maria/ma_create.c:
  Removed wrong cast
storage/myisam/mi_check.c:
  Removed wrong cast
storage/myisam/mi_create.c:
  Removed wrong cast
storage/xtradb/handler/ha_innodb.cc:
  Removed compiler warning on windows