scm: cvs: replace RAILS_ROOT to Rails.root in functional test.
scm: cvs: replace RAILS_ROOT to Rails.root in unit model test.
scm: cvs: replace RAILS_ROOT to Rails.root in unit adapter test.
scm: bazaar: replace RAILS_ROOT to Rails.root in functional test.
scm: bazaar: replace RAILS_ROOT to Rails.root in unit model test.
scm: bazaar: replace RAILS_ROOT to Rails.root in unit adapter test.
scm: filesystem: replace RAILS_ROOT to Rails.root in functional test.
scm: filesystem: replace RAILS_ROOT to Rails.root in unit model test.
scm: filesystem: replace RAILS_ROOT to Rails.root in unit adapter test.
scm: mercurial: replace RAILS_ROOT to Rails.root in functional test.
