convert: refactor sink initialisation, to remove hardcoding of hg
We also introduce options to explicitly set the source and destination
repository types.
Improve testing of corner cases a little.
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
adding b
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
adding b