Don't update MyISAM index file on UPDATE if index is not changed


Build-tools/Do-compile:
  Remove log files as early as possible
Docs/manual.texi:
  Changelog
BitKeeper/etc/ignore:
  Added myisam/test2.MYD myisam/test2.MYI to the ignore list
include/my_semaphore.h:
  Portability fix for SCO and BSDI
innobase/configure.in:
  Don't use inline with openbsd as this cases linker problems.
myisam/mi_update.c:
  Don't update index file on UPDATE if index is not changed
mysys/my_pthread.c:
  Portability fix for hpux
sql/item_cmpfunc.cc:
  Don't convert bigint to bigint