Separate config and index per webapp

[Michael Levy]

I'd like to use Solr for a number of separate projects running on a 
single Tomcat instance; I thought I would have Solr running a separate 
webapp for each project.

I understand that the default location for the solrconfig.xml and 
schema.xml files and for the index are under Tomcat's 
current-working-directory/solr/conf

I am hoping I can change the default location for each webapp.  Thanks!