ipdb: check external calls in compat module
ipdb: check external calls in compat module

Now the compat module checks the exit status of external
processes (like brctl).

Bug-Url: https://github.com/svinota/pyroute2/issues/45
Bug-Url: https://github.com/svinota/pyroute2/issues/46
Bug-Url: https://github.com/svinota/pyroute2/issues/47

simudream/pyroute2,roolebo/pyroute2,vodik/pyroute2,little-dude/pyroute2,nazarewk/pyroute2,tomislacker/python-iproute2,tomislacker/python-iproute2,nazarewk/pyroute2,nazarewk/pyroute2,mtiny/pyroute2,drzaeus77/pyroute2,roolebo/pyroute2,vodik/pyroute2,drzaeus77/pyroute2,little-dude/pyroute2,mtiny/pyroute2,little-dude/pyroute2,simudream/pyroute2