Can now filter by test usages in find results

In the example specs, try find usages on the Account class. With this change, you can now change the filter drop down in the Find Results window to uncheck "Show Unit Test Usages",  and it will remove the occurrences that are used in unit test objects. It will also show the test icon in the drop down lists when invoking Go to Type for e.g. BankingSpecs. Works with 6.1 and 7.1