tests/test-grep.out

convert: readd --filemap

To handle merges correctly, this revision adds a filemap_source class
that wraps a converter_source and does the work necessary to calculate
the subgraph we're interested in.

The wrapped converter_source must provide a new getchangedfiles method
that, given a revision rev, and an index N, returns the list of files
that are different in rev and its Nth parent.

The implementation depends on the ability to skip some revisions and to
change the parents field of the commit objects that we returned earlier.

To make the conversion restartable, we assume the revisons in the
revmapfile are topologically sorted.

% pattern error
grep: invalid match pattern: nothing to repeat!
% simple
port:4:export
port:4:vaportight
port:4:import/export
% all
port:4:4:-:spam:import/export
port:3:4:+:eggs:import/export
port:2:1:-:spam:import
port:2:2:-:spam:export
port:2:1:+:spam:export
port:2:2:+:spam:vaportight
port:2:3:+:spam:import/export
port:1:2:+:eggs:export
port:0:1:+:spam:import
% other
port:4:import/export
% follow
port:0:import
port2:6:4:+:eggs:deport
port:4:4:-:spam:import/export
port:3:4:+:eggs:import/export
port:2:1:-:spam:import
port:2:2:-:spam:export
port:2:1:+:spam:export
port:2:2:+:spam:vaportight
port:2:3:+:spam:import/export
port:1:2:+:eggs:export
port:0:1:+:spam:import
color:3:orange
color:3:+:orange
color:2:-:orange
color:1:+:orange
% issue 685
adding color
color:0:octarine
colour:1:octarine
colour:1:octarine