Utils/Console: doc: added example for adding an overloaded member method to the console

Refactor build system to remove sub-library dependencies

Scheduler/Console: Add 'sys' directory
Scheduler: Implement EventManager and 'sys/scheduler/events' command

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

senfscons: Speed up non-documentation builds (doesn't help much)
Socket/Protocols: Add documentation for sockaddr_cast

Console: Add missing includes to Console.hh
Packets: Documentation clean-up

Scheduler: Make Scheduler more robust by ignoring closed file descriptors

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

Console: Add Console.hh
Console: Add testServer as example to the documentation
Console: Fix overload resolution when adding manually parsed commands
Console: Remove Server::instance() to be more flexible with future extensions

Console: Enum and custom parser documentation

Console: 'Variable' command documentation

Console: Implement custom argument parser support
Utils: Add Boost.Parameter has_parameter helper
senfscons: Show reason (error message) in the CompileCheck builder

Console: Documentation

Console: Pass ParseCommandInfo instead of ArgumentsRange to the callbacks
Console: Add named aliases for operator overloads ('[]' and '()')
Utils: Document, where impl/demangle.h comes from
Updated the 'Setting up a new project using SENF' documentation

Console: Complete the ObjectDirectory proxy interface
Console: Add additional special chars as punctuation chars
Console: Documentation

Console: Implement very (very) fundamental node tree
Console: Implement parser

Examples/Sniffer: Dump all packet registries before starting the packet capture

Socket/Protocols/Inet: Remove not implemented  async resolv constructors (in favor of a later non-member implementation)
Socket/Protocols/Inet: More detailed exceptions thrown by INet4Address / INet6Address

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