and adapt some things.

Note that ha_innodb.cc depends on mysql_tmpfile() being declared in
<mysql/plugin.h>.  Until the function is declared there, you can
uncomment the buggy definition of mysql_tmpfile in ha_innodb.cc.

Remove storage/innobase/*/Makefile.am.  The whole compilation is driven by
storage/innobase/Makefile.am and storage/innobase/plug.in.

plug.in: Declare InnoDB as a dynamic plugin.

ha_innodb.h: Remove the declarations of many global variables.  The variables
are no longer directly referenced outside of storage/innobase.

trx_t: Add the field trx->duplicates.

trx_create(): Initialize the fields trx->active_trans and trx->duplicates.

innobase_query_is_update(): Remove.  Consult trx->duplicates instead.