Design changes in Polyglot
==========================

- SourceLoader is now an interface. Implementation of this interface 
  is now encapsulated in filemanager (ExtFileManager).
- ClassFileLoader is now an interface. Implementation of this interface 
  is now encapsulated in filemanager (ExtFileManager).
- ClassPathLoader has been deleted.
- ClassFile is an interface and ClassFile_c is an implementation of that 
  interface.
- Source and FileSource are now interfaces. Source_c implements FileSource.
- Setting of post compiler classpath and full classpath has been deleted.

Additions to Polyglot
=====================

- ExtensionInfo interface has an additional method classFileLoader which 
  creates a loader that loads .class files from multiple locations.
- FileManager interface, extending StandardJavaFileManager, SourceLoader 
  and ClassFileLoader
- ExtFileManager class, implementing FileManager interface
- SourceObject class, extending SimpleJavaFileObject to provide in-memory 
  objects to hold translated Java code
- StringBuilderWriter class, providing a writer that writes to a 
  StringBuilder

NOTE: Locations in ExtFileManager are set in Main method by calling 
      addLocationsToFileManager method of ExtensionInfo interface.
