net-mgmt/cacti: USE_PHP+= intl pcntl

In version 1.2.23, Cacti's installer checks for the presence of the intl
and pcntl PHP modules. Thus the port ought to depend on those modules.

Also switch to DISTVERSION while we are at it.

See also: https://github.com/Cacti/cacti/commit/27308d84
See also: https://github.com/Cacti/cacti/commit/15cdd4a5
PR: 269022
Approved by: m.muenz@gmail.com (maintainer)