[patchset] Fix sign handling bugs in 2.5

[Ravikiran G Thirumalai]

Here's a patchset to fix sign handling bugs.  This is based on Alan's list,
and is mostly a forward port from 2.4

This patchset is for
- sign handling bug in Decnet
- sign handling bug in epca
- sign handling bug in mpt fusion
- sign handling bug in tun
- sign handling bug in aacraid

The following in Alan's list did not need a fix since it is already taken care
of in current bk.	
- sign handling bug in mwave

Patches will follow this note. Patches compile, but are not really tested.

Thanks,
Kiran