Prevent Eclipse failures with no useful error message when running scripts.

I always work in Eclipse when I have it available even if it takes awhile to figure out most anything. When running Ruby scripts Eclipse seems to want to run the script of whatever tag is currently open. Say you have three tabs, one which the script does nothing but run the classes in each of the other two tabs, and that "start" tab is open. Click Run or Run Configurations or whatever option makes sense in context and it runs! If you have open one of the other class tabs to make a code change and you try to execute your script it will fail with no error message. Always click back to the "start" tab first, then click Run!