Support piping of config files addressing.

This addresses issue #43 . As discussed in that issue thread, the next phase will be integrating sending of configs/content to the workers via IPC, but we could probably use a fresh issue for that. Also, the owner of parsons said he could not yet add in my change[implementing json parsing from a file pointer], because he is working on stuff in dev and planning on rolling out that feature later in October instead of right now. This is why this code implements file content extraction into a string and then the json gets parsed from it.
Actually that is exactly what it does, translating standard errno values to bud_error_t, at the end of the function bud_translate_errno, it invokes bud_error_str(<bud_error_t from errno>, message)