Chapter1
Merge pull request #1 from luisgustavoneves/master

Chapter1
chapters2-4
end of part I
exercisesI
Merge pull request #2 from luisgustavoneves/master

chapters2-4
Few adjustments in Chapter 1
Changed image in Chapter 2
Few adjustments in Chapter 4
Adjustments in Chapter 5
Few adjustments in Chapter 7
Adjustment in Exercises I
Part 1 links updated