Changes

Summary

1. sledgehammer pretty-printing: merge x(1) x(2) to x(1,2)
2. tuned;
3. tuned spelling;
4. support direct rsync from Hg_Sync result directory (usually requires option -d "~~/dirs");
5. clarified signature;
6. more general dirs for Sync.sync;
7. tuned whitespace (amending beb4ee344c22);
8. clarified signature (see also be0ab4b94c62 and c41791ad75c3);
9. tuned;
10. clarified signature;
11. tuned names;
12. proper SSH.System operation;
13. clarified modules;
14. more uniform/robust detect_repository/is_repository: actually check hg root;
15. more uniform local/remote operations;