Arasan 15.6

[jdart]

Arasan 15.6 is available from http://www.arasanchess.org.

Changes in this version:
1) Bug fix in search (affects multi-core searching only).
2) Book selectivity logic changed (50 setting is a bit more selective now).
3) book.random option is fixed (was not working).
4) Book move kibitz for ICS is fixed so that weights are shown normalized and the book selectivity rules are applied.
5) Fix "makebook" program to handle comments after PGN result.

Most of these changes affect the opening book. but there was also a search fix (uninitialized variable). This could be serious, although I have seen no noticeable effects from it so far.

I have some larger changes I am working on, including better performance on multi-core processors, but those are not in this release. They will be in the next major release (July-Aug I expect).