Update version-info
Update version-info file to unicode format.

This makes it work with buggy support for version-info in PyInstaller 2.1.
Update build script.
Rename directory 'src' -> 'xmppvox'.

This change is motivated by the wish to have a package 'xmppvox' and modules/subpackages 'xmppvox.FOO'.
Turn xmppvox into a package.
Change logging output format.
Revised log messages and unicode decoding safety.

This commit removes string formatting operations from log method calls, leaving those operations to be performed by Python's logging module.

The function safe_unicode is an attempt to decode messages from non-English system errors in an exception-free manner. This closes #6, although that same traceback might appear in case of, for instance, failure to connect to a server.

Issue #6 can't be properly fixed without changes to SleekXMPP or dealing with exceptions raised in other threads (under SleekXMPP control).
Upgrade from optparse to argparse.

optparse is deprecated in Python 2.7, argparse is the way to go.
Replace --debug argument with --verbose.

This let us customize several verbosity levels by calling the program with -v, -vv, -vvv, etc.
Add multi-level verbosity levels.
__name__ == '__main__' convention