TRUNK-4015: Application data directory should include web app name

https://issues.openmrs.org/browse/TRUNK-4015

Added feature to create different app data directory for different web apps as per the discussion in the ticket
Set log4jExposeWebAppRoot to false so to avoid webAppRootKey clashes per web app

Set default database name to webapp name e.g. test-deploy.war results into a database called test-deploy.
This allows many web applications to be run on the same instance of tomcat.