adding prioritizing support of portcoreunits
using ACE to set thread priorities
setting future OutputPortUnit thread priority from admin messages
Simplifying PortCoreUnit thread prioritizing using existing ThreadImp::setPriority()
Thread scheduling policy can be set via Thread::setPriority()
removing unused header file (Property.h)
Merge pull request #247 from apaikan/prioritized_thread

Prioritized thread
[idl] remove double slash in path
[doc] document PortCoreUnit
[doc] document yarp::os::impl::PortCoreOutputUnit
Added stdout redirection to yarprun
yarprun with stdout redirection beta.
yarprun stoud in progress
yarprun stdout redirection in progress
added --log option to yarprun server
Added log to stdio mode.
Added log option to yarprun server.
added yarprunLogger application
added method get_messages_by_port_complete() + several improvements
added get_infos method