In dirserv_compute_performance_thresholds, we allocate arrays based
on the length of 'routers', a list of routerinfo_t, but loop over
the nodelist. The 'routers' list may be shorter when relays were
filtered by routers_make_ed_keys_unique, leading to an out-of-bounds
write on directory authorities.

This bug was originally introduced in 26e89742, but it doesn't look
possible to trigger until routers_make_ed_keys_unique was introduced
in 13a31e72.

Fixes bug 19032; bugfix on tor 0.2.8.2-alpha.

Fixes bug 19008. bugfix on 0.2.7.3-rc

Also, put libor-testing.a at a better position in the list of
libraries, to avoid linker errors.

This is a fix, or part of a fix, for 18490.

Conflicts:
	src/test/include.am