(Clone Detection) Database name fixed; same package required; etc.

* Database name is computed differently:
  + Special characters are removed from the name components.
  + Names are converted to all lower case.
  + Package names are part of the database name to avoid ambiguity
    when the same specimen exists in more than one package.
  + Names end with the compler/optimizer pair strings, like "g3_i1".

* The new "comp" property of specimen objects holds the original
  one-character compiler name.  The "compiler" property still holds
  the full name.

* If $same_program is set, then not only do the program names
  (e.g., "id") have to be the same, but also the package names
  (e.g., "coreutils-8.5") have to be the same.