Documentation update in conffiles/

Update the README in conffiles/ and clear out obsolete *.template files from
same.  Add conffiles/survey_info.blank as a clean slate for other surveys to
fill in appropriate survey-specific information.
Doc update re: starsub

Add lanuage in README about the necessity of running
create_local_files/omni_glimpse_starsub.pro before anything else to get the
required star-subtracted GLIMPSE images for the EMAF method.  Also add
warning language in the starsub routine about the CPU-intensive nature of this
routine, but also its one-off runtime.