Merge pull request #188 from FredMaranhao/master

sugestions on documentation
unfuzz some french strings
push 'start' events to avoid any loss of synchronization that may result in git conflicts -- closes #190
Rename GatesBurnedPancake exercise to CohenPancake, just to be fair
Cohen's Algorithm for burned pancakes

Completely overtake the code written by Valentin as it was not
following Cohen's algorithm but some personal adaptation of Gates' algo.

The entities are still to be rewritten, however. Only the mission text
was updated so far.
allow to create upside-down pancakes easily
Cohen is now implemented, so come up with a new idea for future work
implement cohen in java. God that algorithm is not trival :/
kill useless imports
useless cosmetics in the C compilation mechanism
make sure that scala passes the newly added exercises
who broke it this way?? Son, leave your mouse away from my source
also decipher the indentation errors
cleanly react to thread interruption and indentation errors
fix the modality of that dialog (was apparently made visible too early)
proper implementation of the Cohen's pancakes in Python (I hate that language)
cohen pancakes in Scala
Change tabs to 4 spaces in python

This makes it impossible to get messed up with tabs and spaces.
4 spaces is the amount used graphically in jsyntaxpane, so the user
should not notice.

This fixes #73 (but not the java part, which I'll move to a TODO item).
lander exercises in scala
switching to RSyntaxArea instead of JSyntaxPane