More scripts for the OSX buildbot.

[in tools/buildbot/slaves/svn-x64-macosx]
* svnbuild-bindings.sh, svncheck-bindings.sh: New.
* svncheck.sh: Fail if the log file directory can't be created.


git-svn-id: https://svn.apache.org/repos/asf/subversion/trunk@1638707 13f79535-47bb-0310-9956-ffa450edef68