Added layout for hints number.
Created "add letters" feature that adds letters to the partial response
when hints are available and when clicking on the hint button.
Letters are not saved yet
Fullscreen picture displays now the right picture
- Back button now appear correctly when the last level is finished,
regardless the position inside the section.
- Clicking next button on the success dialog will bring to the next
OPENED level
- Entering a section will bring to the first OPENED level. Or the first
closed one if the section is already complete
Merge branch 'add_letters_hint'

Conflicts:
	src/com/quizz/places/fragments/LevelFragment.java