Merge branch 'issue_91' into gemstone2.4
(cherry picked from commit 4a291b655b27a46ff5136676ea7c660d2eb09025)

- Issue #91: Cleaned up MCFileTreeRepository>>repositoryProperties and
  MCFileTreeRepository>>writeRepositoryProperties interaction.

  1. MCFileTreeRepository>>writeRepositoryProperties writes existing
     repositoryPropery dictionary and can be called at any time (like
     when a property is changed).
  2. MCFileTreeRepository>>repositoryProperties signals Error if the
     repository directory does not exist. If the .filetree file is not
     present, it is created with default repository properties.
  3. whenever MCFileTreeRepository>>directory: is called, the repository
     properties are reread from disk.

Conflicts:

	repository/MonticelloFileTree-Core.package/MCFileTreeRepository.class/instance/writeRepositoryProperties.st
	repository/MonticelloFileTree-Core.package/monticello.meta/version
	repository/MonticelloFileTree-Tests.package/monticello.meta/version