Merge branch 'bw/c-plus-plus' into ds/lazy-load-trees

* bw/c-plus-plus: (37 commits) replace: rename 'new' variables trailer: rename 'template' variables tempfile: rename 'template' variables wrapper: rename 'template' variables environment: rename 'namespace' variables diff: rename 'template' variables environment: rename 'template' variables init-db: rename 'template' variables unpack-trees: rename 'new' variables trailer: rename 'new' variables submodule: rename 'new' variables split-index: rename 'new' variables remote: rename 'new' variables ref-filter: rename 'new' variables read-cache: rename 'new' variables line-log: rename 'new' variables imap-send: rename 'new' variables http: rename 'new' variables entry: rename 'new' variables diffcore-delta: rename 'new' variables ...