tests: drop DejaGNU; use Python testrunner for C programs

Move all the C programms into the python test hierarchy and add
python scripts which ensure that they are run when the testsuite
is executed.
tests: Add a .travis.yml so we can use travis-ci
LOCAL: Modify build for arch
LOCAL: start quagga with group as argument
tests: nexthop iteration test might take longer that default timeout
tests: add a test to check zebras rib/fib cleanup

Test that zebra will remove routes from the RIB as soon as the
client that installed it disconnects.
tests: add support for srcdest
tests: add more srcdest rib/fib tests
tests: use simpler linear congruential generator for prng