Added exception handling to web service call
Switched single project to slf4j API

Currently no slf4j binding is added so logging will only produce an error
message.
Added playground servlet
Added slf4j logging
Added binding for slf4j simple
Added logback dependencies to pom.xml
Added logback configuration file
Defined separate profiles for log4j and logback

Default (without -P switch) doesn't package any logger implementation and would
be for environments that already have a logging implementation on the classpath.
Added logger implementation to WAR file name
Made logback profile active by default
Merge branch 'slf4j_logback'