Fix plugin preset tests
Improve tests for plugin
Fix errors revealed by test suite
Only print results for internal/application tests
Rename function to make public

Also add some documentation detailing suggest use of function.
Add documentation for class
Add documentation for class
Add some general class descriptions
Remove skipped tests from FileUtilitiesTest

This class is going to be removed later, so these skips are not necessary to
retain
New class: PluginVst2xId
Scripts to create new class also creates test stub
Remove StringUtilities class