added answers for next chapter
more 'what you've learned?' stuff
added more answers to heterogenous archtitectures chapter
some changes for MIC arch
fixed swapping of strong, weak scaling
fragen ergänzt für kapitel 1 und 2 und typos verbessert
Kapitel 3
Merge pull request #2 from Guerki/master

Merged changes from Guerki (Chapter 1-3) and typo fixes
fixed performance trend (1 -> 3 order magnitudes)
only whitespace cleanups
more whitespace cleanup