adding relocation support

[nicolas de loof <ni...@gmail.com>]

I'd like to add support for archiva-side relocation for maven1 (as in
archiva 0.9)

this requires to get the requested artifact POM and override the
ArtifactReference object prior to fetching the proxy-connectors.
As the ProxiedDavServer make the call to connectors I'll have to place this
relocation-handling code in the ProxiedDavServer, that may not be the better
place.
What architecture would you suggest for an "artifact pre-processor" used as
an interceptor between the DavServer and the managedRepository and it's
proxies ?

Nico.