MFH: r357772

Document dbus local dos

Approved by:	portmgr (miwi)
Update to 1.6.20.

Fix local dos vulnability.
Direct commit to 2014Q2 branch because it using a different version
that head.

Approved by:	portmgr (miwi)
Security:	52bbc7e8-f13c-11e3-bc09-bcaec565249c
Make sysutils/pstree operable in jailed environment.