Support STAGEDIR.

PR:		ports/193168
Submitted by:	Ports Fury.


git-svn-id: svn+ssh://svn.freebsd.org/ports/head@367140 35697150-7ecd-e111-bb59-0022644237b5
- Update to 1.51
- Add LICENSE
- Use options helpers
- Move plugins to a more sensible (IMHO) location


git-svn-id: svn+ssh://svn.freebsd.org/ports/head@367141 35697150-7ecd-e111-bb59-0022644237b5