Fix https://bz.apache.org/bugzilla/show_bug.cgi?id=58255 Document the Semaphore valve. Patch provided by Kyohei Nakamura.
Fix https://bz.apache.org/bugzilla/show_bug.cgi?id=58255
Document the Semaphore valve.
Patch provided by Kyohei Nakamura.

git-svn-id: 79cef5a5a257cc9dbe40a45ac190115b4780e2d0@1696378 13f79535-47bb-0310-9956-ffa450edef68

apache/tomcat,Nickname0806/Test_Q4,Nickname0806/Test_Q4,Nickname0806/Test_Q4,Nickname0806/Test_Q4,apache/tomcat,apache/tomcat,apache/tomcat,apache/tomcat