Upgrade to 2.3.1.

Changelog at <http://cran.r-project.org/web/packages/R2HTML/NEWS>.
Fix security/nss plist
Bump port revision

Submitted by:	rodrigo
Approved by:	bapt (mentor)
MFH:		2014Q4
devel/alog: not jobs safe
emulators/xhomer: not jobs safe
Fix LIB_DEPENDS
Fix a dead symlink
Fix LIB_DEPENDS
Fix LIB_DEPENDS
Fix DEPENDS
www/squid: Upgrade version 3.4.8 => 3.4.9

This update should address some memory leak issues

PR:		193938
PR:		194726
Submitted by:	timp87 (gmail)