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.
The next line [39] set *log4jExposeWebAppRoot* to false. That warning is what prevents deploying more that one web app in the same instance of tomcat. The workaround is to set *log4jExposeWebAppRoot* to *false* or provide each web app with a unique *webAppRootKey*. The only shortcoming of the first approach is that it eliminates the use of log file locations relative to the web application's root directory.