Remove custom DLL loader code from innodb plugin code, use
symbols exported from mysqld.
storage/innodb_plugin/handler/ha_innodb.cc:
Remove a Win32 workaround for current_thd.
The original problem that innodb plugin used
value of TLS variable across DLL boundaries is
solved in MySQL server (current_thd is a function
not TLS variable now)
storage/innodb_plugin/handler/handler0alter.cc:
Remove custom delay loader
storage/innodb_plugin/handler/handler0vars.h:
Remove custom delay loader
storage/innodb_plugin/handler/i_s.cc:
Remove custom delay loader
storage/innodb_plugin/handler/win_delay_loader.cc:
Remove custom delay loader
storage/innodb_plugin/plug.in:
Remove commented out MYSQL_PLUGIN_STATIC,
CMake would not parse that correctly
