dependencies: bumped internal libs to latest versions. - traitlets - ipython-genutils - prompt-toolkit

nix: bumped internal version inside default.nix

release: Bump version 4.7.0 to 4.8.0

release: merge back stable branch into default

Added tag v4.7.0 for changeset de00a831a070

release: Finish preparation for 4.7.0

release: updated pip2nix output for 4.7.0

release: Merge default into stable for release preparation

dependencies: bumped mercurial to 4.1.2

largefiles: added handling of detection and fetching of largefiles. - mercurial largefiles - git lfs - references #2817