gnulib-tool.py: Simplify imports. * pygnulib/enums.py: New file, extracted from pygnulib/GLFileSystem.py. * pygnulib/classes.py: Remove file. * pygnulib/GLFileSystem.py: Remove class CopyAction. Update imports. * pygnulib/GLTestDir.py: Update imports. * pygnulib/GLConfig.py: Update imports and remove 'classes.' prefix. * pygnulib/main.py: Likewise.