Introduce a "directory list" operation at the repos layer. This is thefirst step towards an efficient implementation of 'svn list -r'.The function is straight-forward with support for operation depth andauthz. One important use-case is "find files". To support this withminimal system load, the function allows to specify a glob pattern forthe file name and has an option to only report path and node type.* subversion/include/svn_repos.h (svn_repos_dirent_receiver_t, svn_repos_list): The new API.* subversion/libsvn_repos/list.c (*): New file implementing the new API. Noteworthy: (fill_dirent): Factored out from ... (svn_repos_stat): ... this, which has been moved here from repos.c* subversion/libsvn_repos/repos.c (svn_repos_stat): Move from here to list.c due to shared code.* subversion/tests/libsvn_repos/repos-test.c (test_list): Simple test-case for the new function. (test_funcs): Register new test.