jwrapper: New features added

This may be considered as the first release of jwrapper. Here's a list of the new implemented features since the last PR:
* Grep into `lib/android` to retrieve already wrapped classes
* Auto-generate licence
* Basic user interface added
* Choice between : 
  * Auto-wrap unknown types
  * Comment methods containing unknown types
Normalement, j;encourege pas a positionner NIT_DIR. ce devrait etre utilisé que pour deboquage ou cas bizarres.
Pourquoi ca fonctionne pas sans NIT_DIR?