security/heimdal: Unbreak on DragonFly

The 30 AUG 14 commit to fix libcom_err on some FreeBSD releases crippled
Heimdal on DragonFly such that samba-nsupdate no longer would configure.
The culprit was once again using OSVERSION without checking OPSYS, so
adjusting for OPSYS fixes this regression.
- fix missing date column
- remove defunctional port, old sqlite driver for ruby is missing.
- add RUN_DEPENDS
- update RUN_DEPENDS for rubygems-dbi
- Update to version 7.40.4
- Make heavy dependencies optional

PR:		ports/193327
Submitted by:	tkato432@yahoo.com