Attempt to break the pid lock during startup.

This commit attempts to break the pidfilelock during startup in cases where the
process may have exited without successfully cleaning up the lockfile. It also
attempts to grab the lock before opening the context. Also applied to the
Collector module, which may have been looking for the wrong exception since it
does not rely on a timeout.
Good catch. This looks like an ABC for most errors relating to PIDFiles so I should probably re-import it and keep it as a catch-all.