The problem was that the version was obtained *after* importing the C module. As a result,
recompilation would fail because the library was still in use.
This change also saves the version in the __init__.py file of the lazylinker_ext base module,
so that it can be checked without loading the C module.

- can update shared variables internally, so that it does not need
  Function.__call__ to give correct answers.

- it can loop without returning to Python to implement scan (though this is not
  much faster than a for i in xrange(...) f.fn() type thing

- it is versioned now so that it is recompiled when necessary

- the scan test speed is modified to show these things.

* * *
adding test_speed_rnn to scan_test suite

Prevent the home dir from being a tilde when expanduser fails, which is apparently possible on some systems

Simpler mechanism to allow deep copy of upcast_out in Python 2.4, without the pickle protocol 0 issues -- Thanks James

anymore when pickling functions

Fixed corresponding tests that were using protocol 0.

It was due to the fact the default mode was made non deterministic in 86cac3aa7744

This is especially important under Windows, where one cannot overwrite a
library currently in use.

* * *
new op: Cond
* * *
gpu lazycond optimization