Fixed RPC call context release

Before it always released the Parser, which is aliased with the Streamer, thus
trying to free() an illegal memory chunk.

Andrea Zoppi
Small changes

The configuration files for tools in demos were moved to a misc/ subfolder.
The urosgen.cfg files are updated to the upcoming version of urosgen.py.

Andrea Zoppi
Suppressed timeout error messages for POSIX

Andrea Zoppi
Added service calls and handler macros

Added experimental support for service calls by the node.
Handler macros were added to simplify the user code, while keeping all of the
capabilities of a "flat" handler code base.

Andrea Zoppi
Documentation disclaimer updated

Andrea Zoppi