* slt-changelog: support older versions of git (Ryan Graham)

 * slt-release: don't update production branch (Ryan Graham)

 * slt-release: replace FROM with multi-branch (Ryan Graham)

 * slt-release: dedupe release start/finish parts (Ryan Graham)

 * slt-release: remove -start and -finish commands (Ryan Graham)

 * slt-changelog: refactor internals (Ryan Graham)

 * slt-changelog: make -s consistent with changelog (Ryan Graham)

 * slt-changelog: use topological order of tags (Ryan Graham)

 * slt-stage: ensure version list is a list (Ryan Graham)