Proposed commit log message:
```
Mk/bsd.options.desc.mk: Add shared version control OPTIONS & descriptions
- Add CVS description
- Add DARCS description
- Add GIT description
- Add MERCURIAL description
- Add PERFORCE description
- Rename SVN to SUBVERSION
devel/anjuta:
- Rename OPTION SVN to SUBVERSION
- Sort OPTIONS_DEFINE and OPTIONS_DEFAULT
- Change SUBVERSION_DESC to use the default description
devel/git:
- Rename OPTION P4 to PERFORCE
- Rename OPTION SVN to SUBVERSION
- Change PERFORCE_DESC to use the default description
devel/ocaml-opam:
- Rename OPTION HG to MERCURIAL
- Sort OPTIONS_DEFINE and OPTIONS_DEFAULT
- Change {DARCS,GIT,MERCURIAL}_DESC to use the default description
devel/thunar-vcs-plugin:
- Rename OPTION SVN to SUBVERSION
- Sort OPTIONS_DEFINE
- Change GIT_DESC to use the default description
devel/viewvc:
- Rename OPTION SVN to SUBVERSION
- Sort OPTIONS_DEFINE, OPTIONS_DEFAULT and OPTIONS_SINGLE
devel/viewvc-devel:
- Rename OPTION SVN to SUBVERSION
- Sort OPTIONS_DEFINE, OPTIONS_DEFAULT and OPTIONS_SINGLE
net-mgmt/observium:
- Rename OPTION SVN to SUBVERSION
net-mgmt/rancid3:
- Rename OPTION SVN to SUBVERSION
- Sort OPTIONS_SINGLE_SCM
- Change {CVS,GIT,SUBVERSION}_DESC to use the default description
ports-mgmt/portshaker:
- Rename OPTION SVN to SUBVERSION, HG to MERCURIAL
- Sort OPTIONS_DEFINE
- Change {GIT,MERCURIAL}_DESC to use the default description
security/hydra:
- Rename OPTION SVN to SUBVERSION
security/medusa:
- Rename OPTION SVN to SUBVERSION
- Sort OPTIONS_DEFINE
shells/scponly:
- Rename OPTION SVN to SUBVERSION
- Sort OPTIONS_DEFINE
- Typo fix in SVNSERVE_DESC
www/trac-devel:
- Rename OPTION SVN to SUBVERSION
- Sort OPTIONS_DEFINE, OPTIONS_DEFAULT and OPTIONS_MULTI_DATABASE
- Change {GIT,SUBVERSION}_DESC to use the default description
Reviewed_by: koobs, adamw
Approved by: koobs (ports, mentor)
Differential_Revision: D17459
MFH: No (OPTION description updates)
```