packaging: merge the requirements.txt files for WiX and Inno Now that the content is common, there's no need to have separate files. The content still differs from the non-Windows platforms though. Differential Revision: https://phab.mercurial-scm.org/D8066

packaging: bundle dulwich, keyring, and pywin32-ctypes with WiX too TortoiseHg installs these, which is possibly where they originated (though I would have thought it more likely to be in the WiX installer, given its heritage). When I was working on the TortoiseHg app for Mac (which uses the similar `py2app`), it wasn't possible to use the keyring extension (even externally) without bundling this keyring package into the app. Assuming the same principle applies here, these would enable some common extensions. One of the things that the TortoiseHg packager on macOS does now is it adds the user's local `site-packages` directory to `sys.path`. That would allow the user to install these critical modules in cases like this. But that can probably wait for py3 packaging. The only difference in the installed packages that I see now is WiX also bundles distutils for some reason. I suppose that's not harming anything, so I'm not touching it. The only orphans in the install directories when comparing WiX and Inno now is the Copying.txt vs COPYING.rtf, the two uninstaller files for Inno, and a `Mercurial.url` file in Inno. I have no idea what that is, and it has *.ini syntax with a single field pointing to the Mercurial homepage. Differential Revision: https://phab.mercurial-scm.org/D8062

packaging: bundle the default mercurial.ini template with Inno also This is a step towards converging on the same installer content on Windows. Differential Revision: https://phab.mercurial-scm.org/D8061

packaging: set the FileVersion field in the Inno installer executable Previously, Properties > Details > File version showed "0.0.0.0". This appears to be a longstanding issue, and not part of the refactoring this cycle. Differential Revision: https://phab.mercurial-scm.org/D8060