Revert "Merge branch 'reach_test' of git://github.com/Arceliar/cjdns"

This reverts commit 7107b0598ea0d57b4dac73156ef02eb98ba29736, reversing
changes made to 55760a597f5532b669a715f7e1b3f71db8331411.
Stubbed out refreshReach() which is currently causing problems
nasty bug in routetracer which caused periodic flushing of all routes
Ok I put the updateReach PR back with an extra check against a weird bug which has occasionally been seen in NodeStore