On the 'master-passphrase' branch, revert r1304538 and r1311958, which introduces changes along a direction I've since decided not to go on this branch. (I'm trying to get this crazy playground whipped into some reasonably reviewable shape.)
On the 'master-passphrase' branch, add the use-master-password runtime configuration option and tie all the current auth providers to that feature being disabled. (This won't necessarily be the shipped behavior, but for now it makes for an easy way for me to work without my cached credentials getting in the way.)
* subversion/libsvn_subr/config_file.c (svn_config_ensure): Add configuration template bits for a new 'use-master-password' configuration option.
* subversion/libsvn_subr/cmdline.c (get_old_auth_providers): New function, cored near-verbatim from... (svn_cmdline_create_auth_baton): ...this one, which now only fetches the old auth provider when master passphrase support is disabled.