xapian/xapian — pull request #58 by jaylett (2014-09-14 14:00:54+00:00)
Title: Rishabh & Parth 2012 xapian-letor work

Refactoring on which subsequent GSoC work is based.

Also includes implementations of ListNet & ListMLE which have since been discarded due to possible licensing conflicts (this is noted in the source code in these commits).