Fix python imports in SConscripts

Remove and/or simplify most remaining SENFSCons stuff

Utils: Optimize ExceptionMixin implementation
Utils/Console: Add error logging to UDPServer

PPI: Documentation

Utils/Console: Add chroot() member ConfigBundle

Utils/Exception: message() does not include backtrace informations
fixed some documentation

Utils/Logger: Add optional console node name argument to FileTarget constructor
Utils/Logger: Add 'file' console command to FileTarget returning the target filename
Utils/Logger: Change 'list' console command output to be more readable/consistent

Utils/Console: Allow adding additional config sources to a config bundle while parsing
Utils/Console: Redirect non error console output during configuration to a DiscardStream
Utils/Console: Add more information to path/directory console errors
Utils/Logger: Fix reference to destroyed areas in global destructors

added more tests to increase test coverage

Utils/Logger: /sys/log/self command and more command documentation
Scheduler: Add usingHiresTimers() to query current timer source

Utils/Logger: Quote filename for console directory in FileTarget
Utils/Logger: Add directory node return value to syslog-target and udp-target console commands

Utils/Console: Implement directory return value support in Executor
Utils/Logger: Make file-target return the new directory node

Packets: Allow generic assignment of whole packets

Utils/Logger: Implement dynmaic targets

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