RNS-CR-256: address review comments specific to trafficserver/ts_event.c
Trafficserver/ts_event: switch from TS to IB-based logging where a valid tx is in scope.
Trafficserver: switch remainder of tx-scoped log messages to ib_log framework.
trafficserver: trivial update to consistent naming for txn ctx var.
Trafficserver: rename ib_* vars local to trafficserver plugin
Trafficserver: localise module_data (and hence engine manager) to ts_module
Trafficserver: purge unnecessary/redundant #includes
Trivia ahead of merged push
Trafficserver: replace vestiges of state management in TS plugin, replacing with ironbee's state flags.
nginc build: upgrade to verify downloaded tarball and protect against risk of a trojan
nginx: fix Makefile to add gpg-verify to EXTRA_DIST
nginx: fixup dependencies in Makefile
Fix RNS-1184.  Trafficserver crash where EOS precedes filter initialisation.
Trafficserver: minor cleanups.  Low-hanging fruit from Pull request.
Trafficserver: fix build error
trafficserver: Remove overuser of ironbee transaction logger. RNS-1187
example_servers: Add cast so example servers build on 32-bit. RNS-1178
trafficserver: ultra-safe checking of tx in logging changes from commits ac0046c and 2bd5aa9. RNS-1187
core: Fix AuditEngine ReleventOnly to deal with surrpressed events. RNS-1209
ts_module.c: Reduce txlog rotation time and make a note of missing API for setting size.