Update to apr-util 1.5.4

git-svn-id: http://tortoisesvn.googlecode.com/svn/trunk@25884 4cfb86a4-2c7a-11df-bd14-c1e331e6ceac
Remove unused variable, reported by cppcheck.

git-svn-id: http://tortoisesvn.googlecode.com/svn/trunk@25886 4cfb86a4-2c7a-11df-bd14-c1e331e6ceac
Initialize all member variables, reported by coverity.

git-svn-id: http://tortoisesvn.googlecode.com/svn/trunk@25887 4cfb86a4-2c7a-11df-bd14-c1e331e6ceac