Utils: Rename SafeBool to safe_bool (hmm ...)

Logger: Implemented compile-time configuration support

Fix dependency generation for built programs
Fix depenfencies for auto-generated sources

Make all include path's relative
Add 'senf/Packets.hh', 'senf/PPI.hh' and 'senf/Socket.hh'

Examples/RateStuffer: Use CloneSource module
Exmaples/RateStuffer: Implement using a RateStuffer subnet
PPI: Implement CloneSource
PPI: Add throttle()/unthrottle() to passive debug modules
PPI: Implement DiscardSink
PPI: Implement ThrottleBarrier
PPI: Implement missing unit tests
PPI: Complete the documentation
Scheduler: Improve ClockService performance and remove a race condition
Scheduler: Clean up Scheduler::process()
Utils: Make singleton::instance() protected by default and fix implementation
Remove private members from doxygen documentation

PPI: Add documentation
Utils: Make Logger macros define empty stub types

PPI: Implement ActiveFeederSource and ActiveFeederSink debug composites

PPI: More documentation
PPI: Implement IdleEvent and ActiveFeeder
PPI: add Module::running() member
Scheduler: Remove MinTimeout (not needed with ClockService working)

PPI: Add boolean test for debug modules

PPI: Fix PassivePackeSink: provide front() instead of back() members
PPI: Provide specializations for void-argument callbacks in Events and Route
PPI: Add notifyThrottle/notifyUnthrottle to EventDescriptor
PPI: Re-implement routing classes using a traits-based implementation
PPI: Add Route unit testing (mainly testing throttling)

PPI: Implement throttling
PPI: Implement ModuleManager and ppi::init
PPI: Implement ThresholdQueuing
PPI: Hugely extended routing classes

PPI: Some small bugfixes to make ppitest work (not only compile :-) )
PPI: Add DebugModules