resolving issues raised by rlevick

* removed comments from rakefile
* removed comments from lib/apfel.rb
* fixed require path of parsed_dot_strings in various spec files
  (causing file not found errors in his environment)
* refactored the file-encoding tests against the ascii and utf8
  strings files to be more readable
* refactored the file-encoding test against the utf8 strings file to
  use unix file instead of File.open because File.open specifies an
  encoding to use (defaults to utf8) so the tests were useless for
  ensuring ut8 encoding
* some cosmetic changes
moved the spec/*.strings files to spec/fixtures
improved tests done on utf8 and ascii strings files

* now testing that the first character of the utf8.strings is the BOM
* added german translations and translator comments to the ascii and
  utf strings files
* now testing the keys and values of the ascii and utf8 strings files
moved all the parse tests to apfel_spec.rb