[update] move glue code out of sys

There would be a lot of duplicate code otherwise since all user-space
applications would probably have the same glue code and all kernel ones
have the same glue code too.

Note: this may not end up being true in case of non-POSIX systems, ones
that are not completely compliant or kernels other than Linux.

Signed-off-by: Shahbaz Youssefi <ShabbyX@gmail.com>
[feature] give parameter to callbacks of URT_GLUE

This avoids use of global variables for parameters shared between the
callbacks.  Nonetheless, use of global variables is not completely
eliminated, but that should be ok.

Signed-off-by: Shahbaz Youssefi <ShabbyX@gmail.com>