sigtimedwait & sigwaitinfo implemented

[migthymax]

• refactored access to timer.device
• using sempahore instead of timer_busy
• calling reading/getter functions is made via the structures setup in constructors
• calling setters open each there own timer.device to be lock free
• sigwait is now implemented using sigwaitinfo
• sigwaitinfo is implemented using sigtimedwait
• added/improved test programs
• ...

Important

The behavior that under *nux the signal handlers are run in the context of the main process, cannot be achieved under AmigaOS under all circumstances. Thus the implementation mainly fr the SIGALRM uses a separate AmigaOS Task, which executes the handler for SIGALRM. That again makes some stuff problematic to handle, like if the main process is sleeping and the SIGALRMhandler is repeatable called. For example a SIGINT (CTR-C) is catched by the separate AmigaOS Task. If the Task than checks for an abort, it can lead to a dead lock.