Log Message:
Update to 255:

  Fixed bug in calling getsunmoon.

  Cleaned up extraneous comments.

  Catch alerts without a starting time. Display alerts regarding
  automatic resets in a manner similar to errors.

  Added traps for providing bad file numbers at prompts.

  Second pass at better error trapping. Content checks date(s),
  time, integer(s), presence of @s when @e is given and, when both
  are given, that @s < @e.

  First step to improved error trapping for problematic data files.
  Added check_hash to check for required fields, unknown fields
  and suitable content. Display errors nicely formatted by file
  and line number and write messages to ~/.etmerrors.