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.

changeset:   0:9c2cf2b35aa7
user:        test
date:        Mon Jan 12 13:46:40 1970 +0000
summary:     add foo

changeset:   1:3756a9556b89
tag:         tip
user:        test
date:        Mon Jan 12 13:46:41 1970 +0000
summary:     change foo

2 revisions:
9c2cf2b35aa7
3756a9556b89