fix: Start doomer thread in guile mode

Closes #4
chg: New thread to timeout waiting lists

At the expense of approx 10% of parsing time :-(
new: support for ERSPAN
fix: get rid of old error codes

Shouldn't gcc warn about these?
fix: make doc
chg: bench waiting for read locks separately from write locks
chg: bigger mutex pool for less interlocks
new: Extract subject common-name from TLS certificates
chg: lower log level of DEADLOCK (since it's not much of an issue)
fix: try to never invoque iconv to avoid unpredictable exceptions

Nowhere do we manipulate characters for human reading ; we manipulate
bytes and symbolic values. Raising an exception for any encoding issue
that happen deep within libguile is not acceptable.
fix: waiting list timeouter should also init guile mode
fix: wait list timeouter was supposed to run alone

Replaced the safe_region metaphor by a hopefully less confusing one

Note: this breaks IP test for me as already observed by Frederic.
fix: IP waiting lists timeouter thread must not parse until full reassembly
new: nettop plugin
new: comparison operators for netmatch timestamps
new: NetTop: help screen + better display
fix: display bugs in NetTop when src or dst fields are missing
chg: refresh screen after each keypress
fix: missing initialization of ipv6 info->way
chg: dev: log: Default to stderr.