Release procedure

This page should help us when doing a new release.

1. Bump version number in configure.ac, README.md, in devel branch. Make sure the old version is not left in any other file.
2. Review and update README.md as needed.
3. Merge devel branch into master.
4. Create an annotated gpg-signed tag (git tag -a --sign) pointing to the version branch head
5. Make a clean checkout. Create the tarball (./bootstrap && ./configure && make distcheck).
6. gpg-sign the tarball (gpg -u <IDENTITY> --armor --detach-sig --sign xrdp-*.tar.gz)
7. Create a GitHub release draft choosing the annotated tag already created, upload tarballs and their signature there (xorgxrdp-*.tar.gz, xorgxrdp-*.tar.gz.asc).
8. Make the release draft final