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

Refactor build system to remove sub-library dependencies

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

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

Console: Fix parsing of commands in the presence of default arguments
Console: Generate automatic online help for automatically parsed commands

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: Implement OverloadableCommandNode
Console: Make all virtual functions private
Console: Rename ObjectDirectory to ScopedDirectory
Console: Move non-template dependent ScopedDirectory members to ScopedDirectoryBase
Console: Provide owner-less void specialization of ScopedDirectory