Rationalize example JVM parameters.

Add additional sensible example parameters:
  -XX:+PrintPromotionFailure
  -XX:+PrintFlagsFinal
  -XX:+PrintFlagsInitial

Explain that default heap size is dynamically calculated to avoid
confusion with example hard-coded sizes.

Remove legacy parameters that don't apply anymore, such as:
  wrapper.lockfile
  wrapper.java.app.mainclass
Merge pull request #1731 from apcj/jvm-args

Rationalize example JVM parameters.