Don't build fat jars for example artifacts.

Stop building fat jars for example artifacts (use some trickery with the
exec-maven-plugin to allow running with resources on the classpath). Fix
a few compile errors. Stop requiring file appender in logback. Use
system properties for commonly used dependency versions. Clean up a few
things in the documentation.
Merge pull request #1 from pkwarren/remove_example_fat_jars

Don't build fat jars for example artifacts.