[pLog-svn] Plugin versioning

[Oscar Renalias]

We probably need this feature :) But how to implement it?

I was looking at PHP's version_compare()
(http://www.php.net/manual/en/function.version-compare.php) and we
could probably use it as long as we define our version numbers in a
similar way to what PHP does, i.e. "1.0.1", "1.0" and so on.
Additionally, it supports operans such as ">", "=", "<", "=>" and so
on.

What do you think?

Oscar