add command line option to show review tab at start

Made this quick and dirty with Corey  -
needs to be reviewed at bit more in depth...
review tab: use system property instead of param to show at start

Requires stating the JVM with `-DEnableReviewTab=true`

From sbt, you can do:

    set javaOptions in run += "-DEnableReviewTab=true"

before calling `run`. (Thanks to Jason for that last trick!)
Merge pull request #531 from NetLogo/show-reviewtab-at-start

Add possibility of enabling review tab at start through a system property