- add connection counter to webserver

- other clerical updates related to polling

  . remove possible ineffective type-casts
  . handle volatile declarations for 'next' by union with 'vnext'
- clearical update in StackContext.h

- clerical updates in EventScope.h and webserver.cpp
- try yield-before-poll in poll fibre

- clerical update in EventScope::registerFD(), Fibre.h, testoptions.h
- add multi-scope support to echotest and webserver

- cache context pointers to cluster, poller, event scope in TLS

  -> integrate timer queue
  -> change from global pointer to reference in cluster
- related/necessary clerical updates in BlockingSync.h
- clerical changes & cleanup in poller classes

- remove blocking semantics from nemesis queue
- clerical updates in intrusive stub mpsc queue
- clerical updates in intrusive container declarations for StackContext
- add some 'const' declarations where possible
- split poll vs. block in poller stats

- fix socket options in webserver - primarily for FreeBSD

- clerical updates in BaseProcessor

Set Context::currStack when changing fibres in gdb debugging

See merge request !5

- bug fixes in debugging support
- make poller pthread with tight polling default
- change order of scheduling when using poller fibre

- fix some FreeBSD idiosyncrasies

- re-introduce lfClose and cfibre_close
- use FreeBSD FD registration scheme
- clerical update in Fibre - remove race condition in debug support

Add column header for info fibres, and add tabs between fields

See merge request !3

- clerical updates

Add support for backtraces/info about active fibres

See merge request !2

- remove numerous fastpath/slowpath designations -> impact not clear

Populate filename, line number, and function name in info fibres

See merge request !1