[boost] [patch, 1.34, regex, token] Gcc 4.3 warnings removed

In Gcc 4.3 there is a new warning that is on with -Wall that reports ambigous else. I had to apply this patch to 1.34 (I have not checked trunk) to get rid of the warnings. (This is only from the parts of boost that I actually use, so there might be more.) -- Lgb