Create binaries for core tools

[BuongiornoTexas]

Use pyinstaller to create binary packages for Songlists and importrsm. These can be used by anyone who only needs this functionality and does not want to deal with installing python and managing versioning issues (e.g. #19).

[BuongiornoTexas]

Release 1.2.0rc0 includes binaries for importrsm and songlists for the windows/amd64 platform only (as this is the only platform I have access to).

@sandiz, I'm not sure if people are actively using importrsm with rs-manager these days. If it is still being used, this is a mechanism to deal with version drift in python. These binaries need to be tested by someone other than me, but if they work as expected, we could also bundle win32 and macos binaries, and these should work reliably until the next time steam updates their save file api (even then, I suspect they will need to maintain a lot of the old stuff to support games that are well and truly out of development cycle).