[dsc] DSC release 2.5.0

[Jerry Lundström]

Hi all,

Resolved memory leaks within the IP fragment reassembly code that was
reported by Klaus Darilion (NIC.AT) and added config option to control
some parts of the fragment handling.

  https://www.dns-oarc.net/files/dsc/dsc-2.5.0.tar.gz
  c736a4ea14f72a967db806797d199344119238817b0903a5079792ec541d494d

Packages are available at:

  https://dev.dns-oarc.net/packages/

Fixes:
- Add `pcap_layers_clear_fragments()` to remove old fragments after
  `MAX_FRAG_IDLE` (60 seconds)
- Use correct alloc/free functions for dataset hash
- Fix spacing in dsc.conf(5) man-page

New config option:
- `drop_ip_fragments` will disable IP fragmentation reassembling and
  drop any IP packet that is a fragment (even the first)

Commits:

eaee6c0 Drop IP fragments
3ebb687 Issue #146: Fix leak in fragment handling
9a5e377 Use correct alloc/free
35f663c Fix #107: add const

Cheers,
Jerry