[Bug-gnubg] possible degrade on multithreading

[保坂範行]

Hi, again.

Thank you for quick fix on last bug.
I found an another something critical.

How to reproduce:
1) Build gnubg with  --enable-threads.
2) Look at load graph, it won't go up to around 100%, it remains low level.
   It may also causes UI stucking after requesting match whole match.
(it does not show progress bar moving for while)
   Computer plays so slow, too.

First found in change set of:

Author: c_anthon <c_anthon>
Date:   Thu Oct 1 21:05:53 2009 +0000

    autosave functionallity


Env & prefs etc:
Using Linux, CentOS 5.3
AutoSaveAnalysis is on/off doesn't care.

It looks like mutex problem....

Nori