bundle2: add an unbundle part responsible from unbundling part
We have a new unbundle class and it is now responsible from extracting its own
data. The top level bundler only extracts the header (to detect an end of stream
marker) then leaves everything else to the `unbundlepart` class. The ultimate
goal is to have `unbundlepart` responsible for lazily extracting its payload.
This is mostly code movement.
changeset = 'changeset: {rev}:{node|short}\n{branches}{bookmarks}{tags}phase: {phase}\n{parents}user: {author}\ndate: {date|date}\nsummary: {desc|firstline}\n\n'
changeset_quiet = '{rev}:{node|short}\n'
changeset_verbose = 'changeset: {rev}:{node|short}\n{branches}{bookmarks}{tags}{parents}user: {author}\ndate: {date|date}\n{files}{file_copies_switch}description:\n{desc|strip}\n\n\n'
changeset_debug = 'changeset: {rev}:{node}\n{branches}{bookmarks}{tags}phase: {phase}\n{parents}{manifest}user: {author}\ndate: {date|date}\n{file_mods}{file_adds}{file_dels}{file_copies_switch}{extras}description:\n{desc|strip}\n\n\n'
start_files = 'files: '
file = ' {file}'
end_files = '\n'
start_file_mods = 'files: '
file_mod = ' {file_mod}'
end_file_mods = '\n'
start_file_adds = 'files+: '
file_add = ' {file_add}'
end_file_adds = '\n'
start_file_dels = 'files-: '
file_del = ' {file_del}'
end_file_dels = '\n'
start_file_copies = 'copies: '
file_copy = ' {name} ({source})'
end_file_copies = '\n'
parent = 'parent: {rev}:{node|formatnode}\n'
manifest = 'manifest: {rev}:{node}\n'
branch = 'branch: {branch}\n'
tag = 'tag: {tag}\n'
bookmark = 'bookmark: {bookmark}\n'
extra = 'extra: {key}={value|stringescape}\n'