add some minimal hook in LegacyPathParser to allow exception management in artifact resolution

Some existing artifacts are not available to maven1. jaxen-1.0-FCS-full for example (use by some core maven1 plugins) can only be obtained by specifying a classifier "full".

The maven1 request "/jaxen/jars/jaxen-1.0-FCS-full.jar" is converted as artifact [ jaxen : jaxen : 1.0-FCS-full ], that doesn't exist.

The LegacyPathParser is allready very complex and works for many artifact, but cannot handle classifiers as they can be any string.

A solution to help archiva managers should be to use an resolution exception list :

if ( exceptions.contains( path ) )
{
String exception = exceptions.getProperty( path );
String[] ref = exception.split( ":" );
artifact.setGroupId( ref[0] );
artifact.setArtifactId( ref[1] );
artifact.setVersion( ref[2] );
if ( ref.length > 3 )

{ artifact.setClassifier( ref[3] ); }

return artifact;
}

based on a simple properties file :

jaxen/jars/jaxen-1.0-FCS-full.jar = jaxen:jaxen:1.0-FCS:full

This would allow admins to quickly fix such issues and not require archiva to find a way to make legacy path deterministic.