logilab common python libraries

The astng module was completely rewritten, and some new utility functions were added, as well as two new modules (textutils and shellutils).

This release fixed a bug in asntg that occurred
with Python 2.3 when parsing modules including
an encoding declaration. This caused pylint to
crash. It also removed a debug print statement
from configuration.py that resulted in incorrect
configuration files.

This release fixed a bug in
modutils.modpath_from_file that broke pylint
0.2. It also features a new corbautils module to
simplify the use of omniORB.

This release fixes several problems in the astng module and in the
modutils module, which was partly rewritten to use a different
importation mechanism. A couple of functions have been added to
fileutils.

This release features two new modules for easier
file and syntax tree manipulation. Several
important bugs were fixed in the modutils and
astng modules.