Fix various typos in chapters 1-3
The G in {A,L}GPL does not stand for GNU

but for general...
Cannot should be can not in certain phrases

See http://oxforddictionaries.com/definition/english/cannot?q=cannot
On the one hand..., on the other hand...
Merge pull request #6 from schierlm/typosquatting

michael schierl: Fixing typos in chapters 1-3
2013-08-19: adopting the improvements of M. Schierl into the other parts
92013-08-19: erasing irritations ;-)
2013-0ß8-19: erasing irritations ;-)
2013-08-19: minor improvements
2013-08-19: speficications of being a derivative work added
Merge branch 'kreincke' into integration
2013-08-19: remerging kreincke->integration->master
2013-08-19: typo erased
Merge branch 'kreincke' into integration
Merge branch 'integration'