Reactivated the mechanism that stops the server when the source finishes.

Based on commit ca046df7b, which was reversed later. It is controlled
with the new command line option --autostop of server.py.
Several fixes to the automatic client close code.
First version of the identi.ca download script.
Randomizing timestamps of events gathered from identi.ca.

Since the events are captured every T seconds, timestamps are spread
randomly in that interval, following an exponential distribution. This
avoids the concentration of events at multiples of T.
Improved checks in identi.ca posts.
The identi.ca script writes to a gzip file.

In addition, it closes gracefully when it receives a ctrl-c.
Protected against exceptions in the HTTP requests.
Added the possibility to publishing events to stdout from replay.py.
Improved protection in identica download.
Added a configurable initial delay to replay.py.
Closing the logger at the end of many_clients.py.
Timestamps in replay.py with precision of ms.
Fixed problems with callbacks in replay.py.

- When dumping to stdout the program didn't finish.
- There were errors that could cause the end event to be sent too early.
The initial delay in replay.py was not applied to time generators.

Now it is applied.
Flushing in StdoutPublisher after every event.

Event bodies may not have an end-of-line at the end, in which case
they were buffered for a while...
Fixed an error in replay.py.
Improvements in replay.

- There is a parsing client when --noparse is selected. This way, the
file log can also be written in that situation.

- The reconnect feature in AsyncStreamingClient is disabled when used
from BogusClient. The reconnection system of many_clients is used
instead.
Minimal changes to the quick start guide.
Fixed a bug in the server.
Removed a logging message.