Previously we ensured that it would get called periodically by doing
it from inside the code that added microdescriptors. That won't work
though: it would interfere with our code that tried to read microdescs
from disk initially. Instead, we should consider rebuilding the cache
periodically, and on startup.
Previously on 0.2.2, we'd never clean the cache. Now that we can
clean it, we want to add a condition to rebuild it: that should happen
whenever we have dropped enough microdescriptors that we could save a
lot of space.
No changes file, since 0.2.3 doesn't need one and 0.2.2 already has some
changes files for the backport of the microdesc_clean_cahce() function.
We accidentally freed the internal buffer for bridge stats when we
were writing the bridge stats file or honoring a control port
request for said data. Change the interfaces for
geoip_get_bridge_stats* to prevent these problems, and remove the
offending free/add a tor_strdup.
Fixes bug 1208.
