Distutils' package_data argument doesn't work with py2exe. On the other hand, we don't need the data_files argument (which we're only using under Linux for stuff like our .desktop file and man page that go to system directories), so we'll just use it instead of package_data.
Move trelby's "own" data files installation to distutils' package_data parameter, and (ab)use data_files for stuff that needs to go to system locations (as trelby.desktop, or a prospective manpage) when installing via a package manager, and needs to be omitted when "manually" installing the source tarball.
Motivated to comply better with the Filesystem Hierarchy Standard (FHS), and in preparation of an 'official' Debian package, this involves: * Make trelby code an actual Python module by adding an __init__.py to the src/ directory so it can be installed by setup.py. * Move execution of main() from trelby/trelby.py to a newly created bin/trelby executable python file. * Make src/trelby.py no longer executable, and remove shebang. * setup.py: Add the required distutils attributes and logic to setup.py. In particular, this means modifying bin/trelby at installation time so that it prepends the actual modules installation path to sys.path. * setup.cfg: Install to /opt/trelby by default. * Add MANIFEST.in that lists files to be included in the source tarball that can be generated by invoking python setup.py sdist. * src/misc.py: Make the version constant globally available for use by setup.py; look for the resources directory in ../. * Remove gen_linux_dist.sh, and adapt Makefile accordingly to use different command options of setup.py instead. * Replace /opt paths in trelby.desktop by the new appropriate values. * Simplify build.bat. Most of it is obsolete as we have a proper setup.py now. * Rename README.linux to INSTALL, update contents. * Fix README.dev and t.bat accordingly. * Remove debian/dirs (obsolete), and fix debian/rules for distutils. * debian/install: Install trelby.desktop to /usr/share/applications. * debian/rules: Modify so the Debian package installs to /usr/share/trelby and /usr/bin instead of /opt/trelby.