Make src/test/test-network.sh and friends handle out-of-tree builds
Make src/test/test-network.sh handle out-of-tree builds by removing the assumption that we will always be in the tor directory when building.
Add code to src/test/test-network.sh like:
A similar change was made to src/test/zero_length_keys.sh in legacy/trac#13111 (moved).
Review other scripts to see if they have the same issue.