issue #213

close #213

issue #213

Main Cleanup

- reorganized
- some code blocks are split
- SIGALRM handler for main thread

Cov #1187492, #1187493, #1187494, #1187495, #1138581, #1138582

Nsec No Prove Wildcards Below Dp

Buildsystem Fixes

- libtap is now built separately
- libtap is not linked into server
- tests are built separately
- no need to maintain list of tests in a file

Journal Size Entrylimit

Should also be backported to 1.4

limit

RRSet refactoring - remove RRSIGs, custom memory allocator

- `rrset->rrsigs` removed + code removal where applicable
- mem_ctx_t added to RRSet API, only used in pkt.c now

## State of the review

Up to `nsec_proofs.c`

- Compression hint is now stored in the rrsig_info structure and reused.

- Most changes were in ddns.c: Empty checks used rr_count == 0

- RR insertion function now returns zone RRSet.
- Removed reduntant zone contents / node API functions
- Cleanup.

- Fixed mismatched variables, do not use call directly in for loops.