(Bug #22239) rm EOL f17

We're removing support for Fedora 17, because it's officially gone End
of Life.
Merge pull request #145 from melissaanne/maint/stable/re-141_rm-eol-f17

(Bug #22239) rm EOL f17
(#21211) Fix format string
(#21211) Raise a error on failed reading of cache

Instead of just debug logging this raise a error unless a default value
is supplied.
Merge pull request #151 from dalen/yaml_error

(#21211) Improve error message when hiera fails to load YAML file
(#22777) Propagate errors from cached files

The Hiera::Filecache system would swallow any errors that occurred when
reading or processing a file's contents. This makes it nearly impossible
for any other systems to report errors and where they occurred because
they only show up in logs at debug level.

This changes the Hiera::Filecache to have a new method, read_file, that
does not try to mask errors. The original read method now just handles
any errors that read_file produces. The YAML and JSON backends have been
updated to use read_file so that any malformed YAML or JSON, or
unreadable files, are reported to the caller. This allows, for instance,
puppet to properly report that a value could not be read from hiera when
processing data bindings rather than the value simply not being there
and the user getting the default.