restore the spyies for the release
Fix the temporal view of the sorting world (plus various cleanups)
typo-- and update translations back to 100%
retranslate the sorting world
allow to easily report feedback on JLM
update the engine translations
force the language specific text to be in black

It seems that there is a memory effect on language change: it's set to
visible but it's still red.
select current exercise in navigator (fix #82)
JLM remembers of your programming language (and cleanups)

- various cleanups around the properties on disk
- save the currently used programming language (as long as it's a
  stable one passing all tests, ie either python or java for now)
- mark some strings as translatable on the way (still many to do)
document the changes of the last few days
mark some more strings as translatable
this debug message is useless given the context
Current exercise gets saved in zip files
Progress spys can be turned on/off through properties (plus cleanups)

- ensure that Game.i18n is setup very very soon, and don't change the
  local after initializing the whole thing.
  This really speeds up the start up.
- Add new properties to control the progress spy (twitter/identica)
- Default values of properties can now be saved to populate
  .jlm/properties (and let the user know about them).
- Not all properties are saved to disk: it makes no sense for the user
  to change JLM versions, and I'd prefer hide a bit the teacher mode,
  at least for now.

Sorry for the intermixed commit, coding during vacations lead to
strange results ;)
integrate the pancake exercises into the sorting lesson. still needs a lot of love
Integrate the first exercise of PancakeSort to sort lesson

Rewrote the whole missions, cleanup the entity and pythonize it
cosmetic: rename the pancake exercises
move the pancake universe in the package of the exercises, no need to separate stuff here
Remove any authorship mentions

The git history is here to save who contributed what, and having such
mentions is a very bad idea in a free software: we want contributors
to feel free to improve any part of the code base.

Authorships hinder such good behavior and create frustrations.
major simplification of the pancake universe