windows installer build refinements

windows installer build refinements

this resolves problems of py2exe's modulefinder collection of sources from
.zipped egg files, not by using easy_install to reach the --always-unzip
option, but rather with a small tool which unpacks any zipped egg files found
in misc/dependencies.  this fixes the py2exe build given rollback of the
easy_install stuff which had broken the unix builds.  misc/hatch-eggs.py
performs the honours.

this also includes a misc/sub-ver.py tool which substitutes elements of the
verion number for the current code base (by importing allmydata.__version__
hence make-version should be run first, and the python path carefully managed)
into template files using python's string interpolation of named args from a
dict as the templating syntax.  i.e. %(major)d %(minor)d %(point)d %(nano)d
each expand to the individual components of the version number as codified
by the pyutil.version_class.Version class.  there is also a %(build)s tag
which expands to the string form of the whole version number.  This tool is
used to interpolate the automatically generated version information into the
innosetup source file in a form consistent with innosetup/windows' restrictions