Fix a memory leak in ASCII log writer.
Fix bug when clearing Bloom filter contents.

This patch fixes a bug that occurred when calling the BiF bloomfilter_clear,
which used to not only clear the underlying bit vector but also set its size to
zero. As a result, subsequent element access or computations using the bit
vector size caused erroneous behavior.

Reported by @colonelxc.
Refactor initialization of ASCII log writer options.
Change how input/logging threads set their name.

Setting the thread name on every heartbeat uses a mild amount of
cycles and there's not much benefit to doing it there to get the
additional info regarding the number of processed messages since thread
names usually get truncated to 16 characters and omit that part anyway.
Merge remote-tracking branch 'origin/fastpath'

* origin/fastpath:
  Change how input/logging threads set their name.
  Fix bug when clearing Bloom filter contents.
Merge remote-tracking branch 'origin/topic/jsiwek/ascii-log-memleak-fix'

* origin/topic/jsiwek/ascii-log-memleak-fix:
  Refactor initialization of ASCII log writer options.
  Fix a memory leak in ASCII log writer.