[MRM-565] Archiva 1.0-beta-3 fails in 404 on all legacy request.

[MRM-565] Archiva 1.0-beta-3 fails in 404 on all legacy request.
Using new methods in RepositoryRequest to identify native resource path early and using it.
Adding PolicingServletRequest to deal with bad formatted request paths.
Beefing up RepositoryServletTest to test proxy-less (for now) requests ...
* Browse
* Get Checksum (default layout)
* Get Checksum (legacy layout)
* Get Metadata (versioned + default layout)
* Get Metadata (project + default layout)
* Get Artifact (default layout)
Adding custom mime-types.txt to get proper "Content-Type" headers on GET requests.

git-svn-id: https://svn.apache.org/repos/asf/maven/archiva/trunk@587708 13f79535-47bb-0310-9956-ffa450edef68