Remove obsolete scripts

* find-nearest-rsync was replaced by scap.utils.find_nearest_host
* scap-2 was replaced by inline rsync in scap.tasks.sync_common
* scap-old was replaced by scap
* sync-common-all is a little used alias for scap

Change-Id: If4c1580b04c3a3328f0ca8beeb23058f89f40ba9