Fixes Valgrind warning: 'Conditional jump or move depends on
uninitialised value(s)' in metafile test.

Type libraries are currently parsed in host endianness, so byte arrays
that are going to be interpreted as integers need to be written in the
appropriate byte order.

The stop event should already be signaled by the time we get to that
point since we wait until the child processes terminate in the server
process and the stop event is signaled in the context of one of the
child processes.

Don't call RpcMgmtWaitServerListening if the call to
WaitForSingleObject failed since it is likely that s_stop() hasn't
been called and therefore the call to RpcMgmtWaitServerListening won't
ever return.

rpcrt4: Save the previous BufferLength in test_ndr_buffer and use it when testing the expected buffer length after the NdrFreeBuffer call.

This fixes a test failure on Win2003 upwards when the allocated length
appears to be rounded up to a multiple of 4.

This fixes a number of test failures on XP SP3 and Win2003 upwards.