release: Bump version 4.2.0 to 4.3.0

release: merge back stable branch into default

Added tag v4.2.0 for changeset 21269ba7bafd

release: Finish preparation for 4.2.0

release: updated pip2nix output for 4.2.0

release: Merge default into stable for release preparation

mercurial: Explicitly disable largefiles extension when no config value is present for it. Recent mercurial versions enable the largefiles extension in the hgrc file when cloning from a repo that uses largefiles. This may lead to undesired behaviour. By explicitly disabling it in the baseui object we override the setting in the hgrc file.

hg: Include mercurial patching when using the http app.

nix: Propagate doCheck argument through nix files.

nix: Add releaseName to derivation.