Merge branch 'ds/bundle-uri-3'

Merge branch 'ds/bundle-uri-3'

Define the logical elements of a "bundle list", data structure to
store them in-core, format to transfer them, and code to parse
them.

* ds/bundle-uri-3:
  bundle-uri: suppress stderr from remote-https
  bundle-uri: quiet failed unbundlings
  bundle: add flags to verify_bundle()
  bundle-uri: fetch a list of bundles
  bundle: properly clear all revision flags
  bundle-uri: limit recursion depth for bundle lists
  bundle-uri: parse bundle list in config format
  bundle-uri: unit test "key=value" parsing
  bundle-uri: create "key=value" line parsing
  bundle-uri: create base key-value pair parsing
  bundle-uri: create bundle_list struct and helpers
  bundle-uri: use plain string in find_temp_filename()