Corrected a bug in the implementation of the threaded_once/1-2 built-in  multi-threading predicates (use of detached threads could make the methods fail despite the success of the thread goals).
Corrected a bug in the implementation of the threaded_once/1-2 built-in  multi-threading predicates (use of detached threads could make the methods fail despite the success of the thread goals).

git-svn-id: 4c7b768bc2e2a56aa1c56b1b5a9454ba68342430@4461 ac9c905b-388a-4ddf-9b6a-4063a022bc57

LogtalkDotOrg/logtalk2,LogtalkDotOrg/logtalk2,LogtalkDotOrg/logtalk2,LogtalkDotOrg/logtalk2,LogtalkDotOrg/logtalk2