Utils/Logger: Add more formatting options to SyslogUDPTarget

Utils/Console: Fix rename Target::clear() to Target::flush() to fix name clash (Target / StringTarget)

Refactor build system to remove sub-library dependencies

Utils/Logger: Enhance non-formatted time format to show seconds since first log message

Utils/Logger: Add more consistent and flexible configuration options to SyslogUDPTarget and IOStreamTarget

Clean up all file-defines and remove all tabs

Utils/Logger: More consistently support optional stream spec

Scheduler: Move remaining non-public implementation classes into 'detail' namespace
Adjust rest of SENF accordingly

Scheduler: Add automatic periodic resync to ClockService::abstime() and ClockService::clock()
Scheduler: Add task nameing
Scheduler: BUGFIX: Add missing task-dequeue in FdDispatcher::add()
Scheduler: Add empty() member to all dispatchers
Scheduler: Add eventTime() support to FdManager
Scheduler: Add support for non-pollable file descriptor detection to FdManager and FdDispatcher
Scheduler: Add FIFORunner task watchdog
Scheduler: Add debugging backtrace to FIFORunner
Scheduler: Change senf::Scheduler implementation to use the new dispatcher infrastructure
Scheduler: BUGFIX: Fix access to (possibly) destroyed object in TimerEvent::run()
Utils: Add senf::signalName() helper
Utils/Daemon: Use senf::signalName() in debug messages
Utils/Logger: Fix logger to correctly format the timestamp (the deadlock should be fixed now)
Update scheduler callback signatures to the new API throughout the project
Update documentation

Scheduler: Fix all 'throw SystemException' statments to use SENF_THROW_SYSTEM_EXCEPTION
Scheduler: Implement TimerDispatcher

Fix lot's of inline implementation ordering errors (make sure, all inline functions are implemented before first use)

Console: ConfigFile support

Console: Implement (and document) Server::stop()
Console: Implement working readline C-d and minnimal C-c support
Utils/Logger: Make Stream optional in routing commands

Utils/Logger: Add some internal implementation documentation concerning SENF_LOG_CLASS_AREA()

Utils/Logger: Renoame all 'SENF_LOG_DEF_*' macros to 'SENF_LOG_DEFINE_*'
Utils/Logger: Add documentation on default compile-time limit

Socket/Protocols/INet: Fix INet6SocketAddress base classes