A couple of bug fixes

- fixed implementation bug in bsets.q computation which made log scores very large
- fixed documentation in QuerySimilar and QueryTermSimilar
- changed representation of detailed scores to list of tuples
- fixed detailed scores to take into account c
- changed argsort_best to arg_nlargest and compare it with bottleneck.argpartsort
Revert "A couple of bug fixes"

This reverts commit 305e0fc02d38694f9fdd7ea083491442bef35bd3.
sphinx log score attributes are now initiated to 0