scm: cvs: add -q option at rls.
scm: cvs: add invalid path entries test at unit model test.
scm: cvs: add -q option at rlog.
scm: cvs: add -q option at cat.
scm: cvs: use scm_cmd() in cat.
scm: cvs: add cat test in unit model test.
scm: cvs: use scm_cmd() for diff.
scm: bazaar: use identifier in blame.
scm: git: use revision and scmid in blame.
scm: subversion: use revision in blame.
