Allow Swift daemons and servers to optionally accept a directory as the
configuration parameter. Directory based configuration leverages
ConfigParser's native multi-file support. Files ending in '.conf' in the
given directory are parsed in lexicographical order. Filenames starting with
'.' are ignored. A mixture of file and directory configuration paths is not
supported - if the configuration path is a file behavior is unchanged.
* update swift-init to search for conf.d paths when building servers
(e.g. /etc/swift/proxy-server.conf.d/)
* new script swift-config can be used to inspect the cumulative configuration
* pull a little bit of code out of run_wsgi and test separately
* fix example config bug for the proxy servers client_disconnect option
* added section on directory based configuration to deployment guide
DocImpact
Implements: blueprint confd
Change-Id: I89b0f48e538117f28590cf6698401f74ef58003b
34f5085c3e